[RISCV] Add support for -ffixed-xX flags

This adds support for reserving GPRs such that the compiler will not
choose a register for register allocation. The implementation follows
the same design as for AArch64; each reserved register becomes a target
feature and used for getting the reserved registers for a given
MachineFunction. The backend checks that it does not need to write to
any reserved register; if it does a relevant error is generated.

Differential Revision: https://reviews.llvm.org/D67185

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 4db7cd8..20d7c24 100644 (file)
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -2263,9 +2263,9 @@ def mfix_cortex_a53_835769 : Flag<["-"], "mfix-cortex-a53-835769">,
 def mno_fix_cortex_a53_835769 : Flag<["-"], "mno-fix-cortex-a53-835769">,
   Group<m_aarch64_Features_Group>,
   HelpText<"Don't workaround Cortex-A53 erratum 835769 (AArch64 only)">;
-foreach i = {1-7,9-15,18,20-28} in
-  def ffixed_x#i : Flag<["-"], "ffixed-x"#i>, Group<m_aarch64_Features_Group>,
-    HelpText<"Reserve the "#i#" register (AArch64 only)">;
+foreach i = {1-31} in
+  def ffixed_x#i : Flag<["-"], "ffixed-x"#i>, Group<m_Group>,
+    HelpText<"Reserve the "#i#" register (AArch64/RISC-V only)">;
 
 foreach i = {8-15,18} in
   def fcall_saved_x#i : Flag<["-"], "fcall-saved-x"#i>, Group<m_aarch64_Features_Group>,

diff --git a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
index 624788a..a26f723 100644 (file)
--- a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -367,6 +367,70 @@ void riscv::getRISCVTargetFeatures(const Driver &D, const llvm::Triple &Triple,
   if (MArch.hasValue() && !getArchFeatures(D, *MArch, Features, Args))
     return;
 
+  // Handle features corresponding to "-ffixed-X" options
+  if (Args.hasArg(options::OPT_ffixed_x1))
+    Features.push_back("+reserve-x1");
+  if (Args.hasArg(options::OPT_ffixed_x2))
+    Features.push_back("+reserve-x2");
+  if (Args.hasArg(options::OPT_ffixed_x3))
+    Features.push_back("+reserve-x3");
+  if (Args.hasArg(options::OPT_ffixed_x4))
+    Features.push_back("+reserve-x4");
+  if (Args.hasArg(options::OPT_ffixed_x5))
+    Features.push_back("+reserve-x5");
+  if (Args.hasArg(options::OPT_ffixed_x6))
+    Features.push_back("+reserve-x6");
+  if (Args.hasArg(options::OPT_ffixed_x7))
+    Features.push_back("+reserve-x7");
+  if (Args.hasArg(options::OPT_ffixed_x8))
+    Features.push_back("+reserve-x8");
+  if (Args.hasArg(options::OPT_ffixed_x9))
+    Features.push_back("+reserve-x9");
+  if (Args.hasArg(options::OPT_ffixed_x10))
+    Features.push_back("+reserve-x10");
+  if (Args.hasArg(options::OPT_ffixed_x11))
+    Features.push_back("+reserve-x11");
+  if (Args.hasArg(options::OPT_ffixed_x12))
+    Features.push_back("+reserve-x12");
+  if (Args.hasArg(options::OPT_ffixed_x13))
+    Features.push_back("+reserve-x13");
+  if (Args.hasArg(options::OPT_ffixed_x14))
+    Features.push_back("+reserve-x14");
+  if (Args.hasArg(options::OPT_ffixed_x15))
+    Features.push_back("+reserve-x15");
+  if (Args.hasArg(options::OPT_ffixed_x16))
+    Features.push_back("+reserve-x16");
+  if (Args.hasArg(options::OPT_ffixed_x17))
+    Features.push_back("+reserve-x17");
+  if (Args.hasArg(options::OPT_ffixed_x18))
+    Features.push_back("+reserve-x18");
+  if (Args.hasArg(options::OPT_ffixed_x19))
+    Features.push_back("+reserve-x19");
+  if (Args.hasArg(options::OPT_ffixed_x20))
+    Features.push_back("+reserve-x20");
+  if (Args.hasArg(options::OPT_ffixed_x21))
+    Features.push_back("+reserve-x21");
+  if (Args.hasArg(options::OPT_ffixed_x22))
+    Features.push_back("+reserve-x22");
+  if (Args.hasArg(options::OPT_ffixed_x23))
+    Features.push_back("+reserve-x23");
+  if (Args.hasArg(options::OPT_ffixed_x24))
+    Features.push_back("+reserve-x24");
+  if (Args.hasArg(options::OPT_ffixed_x25))
+    Features.push_back("+reserve-x25");
+  if (Args.hasArg(options::OPT_ffixed_x26))
+    Features.push_back("+reserve-x26");
+  if (Args.hasArg(options::OPT_ffixed_x27))
+    Features.push_back("+reserve-x27");
+  if (Args.hasArg(options::OPT_ffixed_x28))
+    Features.push_back("+reserve-x28");
+  if (Args.hasArg(options::OPT_ffixed_x29))
+    Features.push_back("+reserve-x29");
+  if (Args.hasArg(options::OPT_ffixed_x30))
+    Features.push_back("+reserve-x30");
+  if (Args.hasArg(options::OPT_ffixed_x31))
+    Features.push_back("+reserve-x31");
+
   // -mrelax is default, unless -mno-relax is specified.
   if (Args.hasFlag(options::OPT_mrelax, options::OPT_mno_relax, true))
     Features.push_back("+relax");

diff --git a/clang/test/Driver/riscv-fixed-x-register.c b/clang/test/Driver/riscv-fixed-x-register.c
new file mode 100644 (file)
index 0000000..79df4d9
--- /dev/null
+++ b/clang/test/Driver/riscv-fixed-x-register.c
@@ -0,0 +1,341 @@
+// RUN: %clang -target riscv32 -ffixed-x1 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X1 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x1 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X1 < %t %s
+// CHECK-FIXED-X1: "-target-feature" "+reserve-x1"
+
+// RUN: %clang -target riscv32 -ffixed-x2 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X2 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x2 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X2 < %t %s
+// CHECK-FIXED-X2: "-target-feature" "+reserve-x2"
+
+// RUN: %clang -target riscv32 -ffixed-x3 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X3 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x3 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X3 < %t %s
+// CHECK-FIXED-X3: "-target-feature" "+reserve-x3"
+
+// RUN: %clang -target riscv32 -ffixed-x4 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X4 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x4 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X4 < %t %s
+// CHECK-FIXED-X4: "-target-feature" "+reserve-x4"
+
+// RUN: %clang -target riscv32 -ffixed-x5 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X5 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x5 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X5 < %t %s
+// CHECK-FIXED-X5: "-target-feature" "+reserve-x5"
+
+// RUN: %clang -target riscv32 -ffixed-x6 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X6 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x6 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X6 < %t %s
+// CHECK-FIXED-X6: "-target-feature" "+reserve-x6"
+
+// RUN: %clang -target riscv32 -ffixed-x7 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X7 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x7 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X7 < %t %s
+// CHECK-FIXED-X7: "-target-feature" "+reserve-x7"
+
+// RUN: %clang -target riscv32 -ffixed-x8 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X8 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x8 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X8 < %t %s
+// CHECK-FIXED-X8: "-target-feature" "+reserve-x8"
+
+// RUN: %clang -target riscv32 -ffixed-x9 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X9 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x9 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X9 < %t %s
+// CHECK-FIXED-X9: "-target-feature" "+reserve-x9"
+
+// RUN: %clang -target riscv32 -ffixed-x10 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X10 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x10 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X10 < %t %s
+// CHECK-FIXED-X10: "-target-feature" "+reserve-x10"
+
+// RUN: %clang -target riscv32 -ffixed-x11 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X11 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x11 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X11 < %t %s
+// CHECK-FIXED-X11: "-target-feature" "+reserve-x11"
+
+// RUN: %clang -target riscv32 -ffixed-x12 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X12 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x12 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X12 < %t %s
+// CHECK-FIXED-X12: "-target-feature" "+reserve-x12"
+
+// RUN: %clang -target riscv32 -ffixed-x13 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X13 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x13 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X13 < %t %s
+// CHECK-FIXED-X13: "-target-feature" "+reserve-x13"
+
+// RUN: %clang -target riscv32 -ffixed-x14 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X14 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x14 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X14 < %t %s
+// CHECK-FIXED-X14: "-target-feature" "+reserve-x14"
+
+// RUN: %clang -target riscv32 -ffixed-x15 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X15 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x15 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X15 < %t %s
+// CHECK-FIXED-X15: "-target-feature" "+reserve-x15"
+
+// RUN: %clang -target riscv32 -ffixed-x16 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X16 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x16 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X16 < %t %s
+// CHECK-FIXED-X16: "-target-feature" "+reserve-x16"
+
+// RUN: %clang -target riscv32 -ffixed-x17 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X17 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x17 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X17 < %t %s
+// CHECK-FIXED-X17: "-target-feature" "+reserve-x17"
+
+// RUN: %clang -target riscv32 -ffixed-x18 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X18 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x18 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X18 < %t %s
+// CHECK-FIXED-X18: "-target-feature" "+reserve-x18"
+
+// RUN: %clang -target riscv32 -ffixed-x19 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X19 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x19 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X19 < %t %s
+// CHECK-FIXED-X19: "-target-feature" "+reserve-x19"
+
+// RUN: %clang -target riscv32 -ffixed-x20 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X20 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x20 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X20 < %t %s
+// CHECK-FIXED-X20: "-target-feature" "+reserve-x20"
+
+// RUN: %clang -target riscv32 -ffixed-x21 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X21 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x21 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X21 < %t %s
+// CHECK-FIXED-X21: "-target-feature" "+reserve-x21"
+
+// RUN: %clang -target riscv32 -ffixed-x22 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X22 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x22 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X22 < %t %s
+// CHECK-FIXED-X22: "-target-feature" "+reserve-x22"
+
+// RUN: %clang -target riscv32 -ffixed-x23 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X23 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x23 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X23 < %t %s
+// CHECK-FIXED-X23: "-target-feature" "+reserve-x23"
+
+// RUN: %clang -target riscv32 -ffixed-x24 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X24 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x24 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X24 < %t %s
+// CHECK-FIXED-X24: "-target-feature" "+reserve-x24"
+
+// RUN: %clang -target riscv32 -ffixed-x25 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X25 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x25 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X25 < %t %s
+// CHECK-FIXED-X25: "-target-feature" "+reserve-x25"
+
+// RUN: %clang -target riscv32 -ffixed-x26 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X26 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x26 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X26 < %t %s
+// CHECK-FIXED-X26: "-target-feature" "+reserve-x26"
+
+// RUN: %clang -target riscv32 -ffixed-x27 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X27 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x27 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X27 < %t %s
+// CHECK-FIXED-X27: "-target-feature" "+reserve-x27"
+
+// RUN: %clang -target riscv32 -ffixed-x28 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X28 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x28 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X28 < %t %s
+// CHECK-FIXED-X28: "-target-feature" "+reserve-x28"
+
+// RUN: %clang -target riscv32 -ffixed-x29 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X29 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x29 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X29 < %t %s
+// CHECK-FIXED-X29: "-target-feature" "+reserve-x29"
+
+// RUN: %clang -target riscv32 -ffixed-x30 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X30 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x30 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X30 < %t %s
+// CHECK-FIXED-X30: "-target-feature" "+reserve-x30"
+
+// RUN: %clang -target riscv32 -ffixed-x31 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X31 < %t %s
+// RUN: %clang -target riscv64 -ffixed-x31 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X31 < %t %s
+// CHECK-FIXED-X31: "-target-feature" "+reserve-x31"
+
+// Test multiple of reserve-x# options together.
+// RUN: %clang -target riscv32 \
+// RUN: -ffixed-x1 \
+// RUN: -ffixed-x2 \
+// RUN: -ffixed-x18 \
+// RUN: -### %s 2> %t
+// RUN: FileCheck \
+// RUN: --check-prefix=CHECK-FIXED-X1 \
+// RUN: --check-prefix=CHECK-FIXED-X2 \
+// RUN: --check-prefix=CHECK-FIXED-X18 \
+// RUN: < %t %s
+// RUN: %clang -target riscv64 \
+// RUN: -ffixed-x1 \
+// RUN: -ffixed-x2 \
+// RUN: -ffixed-x18 \
+// RUN: -### %s 2> %t
+// RUN: FileCheck \
+// RUN: --check-prefix=CHECK-FIXED-X1 \
+// RUN: --check-prefix=CHECK-FIXED-X2 \
+// RUN: --check-prefix=CHECK-FIXED-X18 \
+// RUN: < %t %s
+
+// Test all reserve-x# options together.
+// RUN: %clang -target riscv32 \
+// RUN: -ffixed-x1 \
+// RUN: -ffixed-x2 \
+// RUN: -ffixed-x3 \
+// RUN: -ffixed-x4 \
+// RUN: -ffixed-x5 \
+// RUN: -ffixed-x6 \
+// RUN: -ffixed-x7 \
+// RUN: -ffixed-x8 \
+// RUN: -ffixed-x9 \
+// RUN: -ffixed-x10 \
+// RUN: -ffixed-x11 \
+// RUN: -ffixed-x12 \
+// RUN: -ffixed-x13 \
+// RUN: -ffixed-x14 \
+// RUN: -ffixed-x15 \
+// RUN: -ffixed-x16 \
+// RUN: -ffixed-x17 \
+// RUN: -ffixed-x18 \
+// RUN: -ffixed-x19 \
+// RUN: -ffixed-x20 \
+// RUN: -ffixed-x21 \
+// RUN: -ffixed-x22 \
+// RUN: -ffixed-x23 \
+// RUN: -ffixed-x24 \
+// RUN: -ffixed-x25 \
+// RUN: -ffixed-x26 \
+// RUN: -ffixed-x27 \
+// RUN: -ffixed-x28 \
+// RUN: -ffixed-x29 \
+// RUN: -ffixed-x30 \
+// RUN: -ffixed-x31 \
+// RUN: -### %s 2> %t
+// RUN: FileCheck \
+// RUN: --check-prefix=CHECK-FIXED-X1 \
+// RUN: --check-prefix=CHECK-FIXED-X2 \
+// RUN: --check-prefix=CHECK-FIXED-X3 \
+// RUN: --check-prefix=CHECK-FIXED-X4 \
+// RUN: --check-prefix=CHECK-FIXED-X5 \
+// RUN: --check-prefix=CHECK-FIXED-X6 \
+// RUN: --check-prefix=CHECK-FIXED-X7 \
+// RUN: --check-prefix=CHECK-FIXED-X8 \
+// RUN: --check-prefix=CHECK-FIXED-X9 \
+// RUN: --check-prefix=CHECK-FIXED-X10 \
+// RUN: --check-prefix=CHECK-FIXED-X11 \
+// RUN: --check-prefix=CHECK-FIXED-X12 \
+// RUN: --check-prefix=CHECK-FIXED-X13 \
+// RUN: --check-prefix=CHECK-FIXED-X14 \
+// RUN: --check-prefix=CHECK-FIXED-X15 \
+// RUN: --check-prefix=CHECK-FIXED-X16 \
+// RUN: --check-prefix=CHECK-FIXED-X17 \
+// RUN: --check-prefix=CHECK-FIXED-X18 \
+// RUN: --check-prefix=CHECK-FIXED-X19 \
+// RUN: --check-prefix=CHECK-FIXED-X20 \
+// RUN: --check-prefix=CHECK-FIXED-X21 \
+// RUN: --check-prefix=CHECK-FIXED-X22 \
+// RUN: --check-prefix=CHECK-FIXED-X23 \
+// RUN: --check-prefix=CHECK-FIXED-X24 \
+// RUN: --check-prefix=CHECK-FIXED-X25 \
+// RUN: --check-prefix=CHECK-FIXED-X26 \
+// RUN: --check-prefix=CHECK-FIXED-X27 \
+// RUN: --check-prefix=CHECK-FIXED-X28 \
+// RUN: --check-prefix=CHECK-FIXED-X29 \
+// RUN: --check-prefix=CHECK-FIXED-X30 \
+// RUN: --check-prefix=CHECK-FIXED-X31 \
+// RUN: < %t %s
+// RUN: %clang -target riscv64 \
+// RUN: -ffixed-x1 \
+// RUN: -ffixed-x2 \
+// RUN: -ffixed-x3 \
+// RUN: -ffixed-x4 \
+// RUN: -ffixed-x5 \
+// RUN: -ffixed-x6 \
+// RUN: -ffixed-x7 \
+// RUN: -ffixed-x8 \
+// RUN: -ffixed-x9 \
+// RUN: -ffixed-x10 \
+// RUN: -ffixed-x11 \
+// RUN: -ffixed-x12 \
+// RUN: -ffixed-x13 \
+// RUN: -ffixed-x14 \
+// RUN: -ffixed-x15 \
+// RUN: -ffixed-x16 \
+// RUN: -ffixed-x17 \
+// RUN: -ffixed-x18 \
+// RUN: -ffixed-x19 \
+// RUN: -ffixed-x20 \
+// RUN: -ffixed-x21 \
+// RUN: -ffixed-x22 \
+// RUN: -ffixed-x23 \
+// RUN: -ffixed-x24 \
+// RUN: -ffixed-x25 \
+// RUN: -ffixed-x26 \
+// RUN: -ffixed-x27 \
+// RUN: -ffixed-x28 \
+// RUN: -ffixed-x29 \
+// RUN: -ffixed-x30 \
+// RUN: -ffixed-x31 \
+// RUN: -### %s 2> %t
+// RUN: FileCheck \
+// RUN: --check-prefix=CHECK-FIXED-X1 \
+// RUN: --check-prefix=CHECK-FIXED-X2 \
+// RUN: --check-prefix=CHECK-FIXED-X3 \
+// RUN: --check-prefix=CHECK-FIXED-X4 \
+// RUN: --check-prefix=CHECK-FIXED-X5 \
+// RUN: --check-prefix=CHECK-FIXED-X6 \
+// RUN: --check-prefix=CHECK-FIXED-X7 \
+// RUN: --check-prefix=CHECK-FIXED-X8 \
+// RUN: --check-prefix=CHECK-FIXED-X9 \
+// RUN: --check-prefix=CHECK-FIXED-X10 \
+// RUN: --check-prefix=CHECK-FIXED-X11 \
+// RUN: --check-prefix=CHECK-FIXED-X12 \
+// RUN: --check-prefix=CHECK-FIXED-X13 \
+// RUN: --check-prefix=CHECK-FIXED-X14 \
+// RUN: --check-prefix=CHECK-FIXED-X15 \
+// RUN: --check-prefix=CHECK-FIXED-X16 \
+// RUN: --check-prefix=CHECK-FIXED-X17 \
+// RUN: --check-prefix=CHECK-FIXED-X18 \
+// RUN: --check-prefix=CHECK-FIXED-X19 \
+// RUN: --check-prefix=CHECK-FIXED-X20 \
+// RUN: --check-prefix=CHECK-FIXED-X21 \
+// RUN: --check-prefix=CHECK-FIXED-X22 \
+// RUN: --check-prefix=CHECK-FIXED-X23 \
+// RUN: --check-prefix=CHECK-FIXED-X24 \
+// RUN: --check-prefix=CHECK-FIXED-X25 \
+// RUN: --check-prefix=CHECK-FIXED-X26 \
+// RUN: --check-prefix=CHECK-FIXED-X27 \
+// RUN: --check-prefix=CHECK-FIXED-X28 \
+// RUN: --check-prefix=CHECK-FIXED-X29 \
+// RUN: --check-prefix=CHECK-FIXED-X30 \
+// RUN: --check-prefix=CHECK-FIXED-X31 \
+// RUN: < %t %s

diff --git a/llvm/lib/Target/RISCV/RISCV.td b/llvm/lib/Target/RISCV/RISCV.td
index 46530a8..70d87d6 100644 (file)
--- a/llvm/lib/Target/RISCV/RISCV.td
+++ b/llvm/lib/Target/RISCV/RISCV.td
@@ -69,6 +69,11 @@ def FeatureRelax
     : SubtargetFeature<"relax", "EnableLinkerRelax", "true",
                        "Enable Linker relaxation.">;
 
+foreach i = {1-31} in
+    def FeatureReserveX#i :
+        SubtargetFeature<"reserve-x"#i, "UserReservedRegister[RISCV::X"#i#"]",
+                         "true", "Reserve X"#i>;
+
 //===----------------------------------------------------------------------===//
 // Named operands for CSR instructions.
 //===----------------------------------------------------------------------===//

diff --git a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
index 6b6f62e..daa7b7a 100644 (file)
--- a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
@@ -18,6 +18,7 @@
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/MC/MCDwarf.h"
 
 using namespace llvm;
@@ -131,6 +132,12 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
   if (StackSize == 0 && !MFI.adjustsStack())
     return;
 
+  // If the stack pointer has been marked as reserved, then produce an error if
+  // the frame requires stack allocation
+  if (STI.isRegisterReservedByUser(SPReg))
+    MF.getFunction().getContext().diagnose(DiagnosticInfoUnsupported{
+        MF.getFunction(), "Stack pointer required, but has been reserved."});
+
   uint64_t FirstSPAdjustAmount = getFirstSPAdjustAmount(MF);
   // Split the SP adjustment to reduce the offsets of callee saved spill.
   if (FirstSPAdjustAmount)
@@ -167,6 +174,10 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
 
   // Generate new FP.
   if (hasFP(MF)) {
+    if (STI.isRegisterReservedByUser(FPReg))
+      MF.getFunction().getContext().diagnose(DiagnosticInfoUnsupported{
+          MF.getFunction(), "Frame pointer required, but has been reserved."});
+
     adjustReg(MBB, MBBI, DL, FPReg, SPReg,
               StackSize - RVFI->getVarArgsSaveSize(), MachineInstr::FrameSetup);
 

diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index dc829fc..b56d951 100644 (file)
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -2247,6 +2247,16 @@ SDValue RISCVTargetLowering::LowerCall(CallLoweringInfo &CLI,
     Glue = Chain.getValue(1);
   }
 
+  // Validate that none of the argument registers have been marked as
+  // reserved, if so report an error. Do the same for the return address if this
+  // is not a tailcall.
+  validateCCReservedRegs(RegsToPass, MF);
+  if (!IsTailCall &&
+      MF.getSubtarget<RISCVSubtarget>().isRegisterReservedByUser(RISCV::X1))
+    MF.getFunction().getContext().diagnose(DiagnosticInfoUnsupported{
+        MF.getFunction(),
+        "Return address register required, but has been reserved."});
+
   // If the callee is a GlobalAddress/ExternalSymbol node, turn it into a
   // TargetGlobalAddress/TargetExternalSymbol node so that legalize won't
   // split it and then direct call can be matched by PseudoCALL.
@@ -2362,6 +2372,9 @@ RISCVTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
                                  const SmallVectorImpl<ISD::OutputArg> &Outs,
                                  const SmallVectorImpl<SDValue> &OutVals,
                                  const SDLoc &DL, SelectionDAG &DAG) const {
+  const MachineFunction &MF = DAG.getMachineFunction();
+  const RISCVSubtarget &STI = MF.getSubtarget<RISCVSubtarget>();
+
   // Stores the assignment of the return value to a location.
   SmallVector<CCValAssign, 16> RVLocs;
 
@@ -2391,6 +2404,13 @@ RISCVTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
       Register RegLo = VA.getLocReg();
       assert(RegLo < RISCV::X31 && "Invalid register pair");
       Register RegHi = RegLo + 1;
+
+      if (STI.isRegisterReservedByUser(RegLo) ||
+          STI.isRegisterReservedByUser(RegHi))
+        MF.getFunction().getContext().diagnose(DiagnosticInfoUnsupported{
+            MF.getFunction(),
+            "Return value register required, but has been reserved."});
+
       Chain = DAG.getCopyToReg(Chain, DL, RegLo, Lo, Glue);
       Glue = Chain.getValue(1);
       RetOps.push_back(DAG.getRegister(RegLo, MVT::i32));
@@ -2402,6 +2422,11 @@ RISCVTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
       Val = convertValVTToLocVT(DAG, Val, VA, DL);
       Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Val, Glue);
 
+      if (STI.isRegisterReservedByUser(VA.getLocReg()))
+        MF.getFunction().getContext().diagnose(DiagnosticInfoUnsupported{
+            MF.getFunction(),
+            "Return value register required, but has been reserved."});
+
       // Guarantee that all emitted copies are stuck together.
       Glue = Chain.getValue(1);
       RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
@@ -2440,6 +2465,19 @@ RISCVTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
   return DAG.getNode(RISCVISD::RET_FLAG, DL, MVT::Other, RetOps);
 }
 
+void RISCVTargetLowering::validateCCReservedRegs(
+    const SmallVectorImpl<std::pair<llvm::Register, llvm::SDValue>> &Regs,
+    MachineFunction &MF) const {
+  const Function &F = MF.getFunction();
+  const RISCVSubtarget &STI = MF.getSubtarget<RISCVSubtarget>();
+
+  if (std::any_of(std::begin(Regs), std::end(Regs), [&STI](auto Reg) {
+        return STI.isRegisterReservedByUser(Reg.first);
+      }))
+    F.getContext().diagnose(DiagnosticInfoUnsupported{
+        F, "Argument register required, but has been reserved."});
+}
+
 const char *RISCVTargetLowering::getTargetNodeName(unsigned Opcode) const {
   switch ((RISCVISD::NodeType)Opcode) {
   case RISCVISD::FIRST_NUMBER:

diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.h b/llvm/lib/Target/RISCV/RISCVISelLowering.h
index 18fc735..0d2d14e 100644 (file)
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.h
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.h
@@ -210,6 +210,12 @@ private:
                                    Value *AlignedAddr, Value *CmpVal,
                                    Value *NewVal, Value *Mask,
                                    AtomicOrdering Ord) const override;
+
+  /// Generate error diagnostics if any register used by CC has been marked
+  /// reserved.
+  void validateCCReservedRegs(
+      const SmallVectorImpl<std::pair<llvm::Register, llvm::SDValue>> &Regs,
+      MachineFunction &MF) const;
 };
 }
 

diff --git a/llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp b/llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp
index 6655768..65a7e41 100644 (file)
--- a/llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp
@@ -69,6 +69,12 @@ BitVector RISCVRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
   const TargetFrameLowering *TFI = getFrameLowering(MF);
   BitVector Reserved(getNumRegs());
 
+  // Mark any registers requested to be reserved as such
+  for (size_t Reg = 0; Reg < getNumRegs(); Reg++) {
+    if (MF.getSubtarget<RISCVSubtarget>().isRegisterReservedByUser(Reg))
+      markSuperRegs(Reserved, Reg);
+  }
+
   // Use markSuperRegs to ensure any register aliases are also reserved
   markSuperRegs(Reserved, RISCV::X0); // zero
   markSuperRegs(Reserved, RISCV::X1); // ra
@@ -81,6 +87,11 @@ BitVector RISCVRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
   return Reserved;
 }
 
+bool RISCVRegisterInfo::isAsmClobberable(const MachineFunction &MF,
+                                         unsigned PhysReg) const {
+  return !MF.getSubtarget<RISCVSubtarget>().isRegisterReservedByUser(PhysReg);
+}
+
 bool RISCVRegisterInfo::isConstantPhysReg(unsigned PhysReg) const {
   return PhysReg == RISCV::X0;
 }

diff --git a/llvm/lib/Target/RISCV/RISCVRegisterInfo.h b/llvm/lib/Target/RISCV/RISCVRegisterInfo.h
index 56a50fe..30b6395 100644 (file)
--- a/llvm/lib/Target/RISCV/RISCVRegisterInfo.h
+++ b/llvm/lib/Target/RISCV/RISCVRegisterInfo.h
@@ -30,6 +30,8 @@ struct RISCVRegisterInfo : public RISCVGenRegisterInfo {
   const MCPhysReg *getCalleeSavedRegs(const MachineFunction *MF) const override;
 
   BitVector getReservedRegs(const MachineFunction &MF) const override;
+  bool isAsmClobberable(const MachineFunction &MF,
+                        unsigned PhysReg) const override;
 
   bool isConstantPhysReg(unsigned PhysReg) const override;
 

diff --git a/llvm/lib/Target/RISCV/RISCVSubtarget.cpp b/llvm/lib/Target/RISCV/RISCVSubtarget.cpp
index f114c6a..83e7e2d 100644 (file)
--- a/llvm/lib/Target/RISCV/RISCVSubtarget.cpp
+++ b/llvm/lib/Target/RISCV/RISCVSubtarget.cpp
@@ -50,6 +50,7 @@ RISCVSubtarget &RISCVSubtarget::initializeSubtargetDependencies(
 RISCVSubtarget::RISCVSubtarget(const Triple &TT, StringRef CPU, StringRef FS,
                                StringRef ABIName, const TargetMachine &TM)
     : RISCVGenSubtargetInfo(TT, CPU, FS),
+      UserReservedRegister(RISCV::NUM_TARGET_REGS),
       FrameLowering(initializeSubtargetDependencies(TT, CPU, FS, ABIName)),
       InstrInfo(*this), RegInfo(getHwMode()), TLInfo(TM, *this) {
   CallLoweringInfo.reset(new RISCVCallLowering(*getTargetLowering()));

diff --git a/llvm/lib/Target/RISCV/RISCVSubtarget.h b/llvm/lib/Target/RISCV/RISCVSubtarget.h
index 7d0373a..605d4ab 100644 (file)
--- a/llvm/lib/Target/RISCV/RISCVSubtarget.h
+++ b/llvm/lib/Target/RISCV/RISCVSubtarget.h
@@ -46,6 +46,7 @@ class RISCVSubtarget : public RISCVGenSubtargetInfo {
   unsigned XLen = 32;
   MVT XLenVT = MVT::i32;
   RISCVABI::ABI TargetABI = RISCVABI::ABI_Unknown;
+  BitVector UserReservedRegister;
   RISCVFrameLowering FrameLowering;
   RISCVInstrInfo InstrInfo;
   RISCVRegisterInfo RegInfo;
@@ -93,6 +94,10 @@ public:
   MVT getXLenVT() const { return XLenVT; }
   unsigned getXLen() const { return XLen; }
   RISCVABI::ABI getTargetABI() const { return TargetABI; }
+  bool isRegisterReservedByUser(Register i) const {
+    assert(i < RISCV::NUM_TARGET_REGS && "Register out of range");
+    return UserReservedRegister[i];
+  }
 
 protected:
   // GlobalISel related APIs.

diff --git a/llvm/test/CodeGen/RISCV/reserved-reg-errors.ll b/llvm/test/CodeGen/RISCV/reserved-reg-errors.ll
new file mode 100644 (file)
index 0000000..f10ef9a
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/reserved-reg-errors.ll
@@ -0,0 +1,36 @@
+; RUN: not llc -mtriple=riscv32 -mattr=+reserve-x1 < %s 2>&1 | FileCheck %s -check-prefix=X1
+; RUN: not llc -mtriple=riscv64 -mattr=+reserve-x1 < %s 2>&1 | FileCheck %s -check-prefix=X1
+; RUN: not llc -mtriple=riscv32 -mattr=+reserve-x2 < %s 2>&1 | FileCheck %s -check-prefix=X2
+; RUN: not llc -mtriple=riscv64 -mattr=+reserve-x2 < %s 2>&1 | FileCheck %s -check-prefix=X2
+; RUN: not llc -mtriple=riscv32 -mattr=+reserve-x8 < %s 2>&1 | FileCheck %s -check-prefix=X8
+; RUN: not llc -mtriple=riscv64 -mattr=+reserve-x8 < %s 2>&1 | FileCheck %s -check-prefix=X8
+; RUN: not llc -mtriple=riscv32 -mattr=+reserve-x10 < %s 2>&1 | FileCheck %s -check-prefix=X10
+; RUN: not llc -mtriple=riscv64 -mattr=+reserve-x10 < %s 2>&1 | FileCheck %s -check-prefix=X10
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x11 < %s 2>&1 | FileCheck %s -check-prefix=X11
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x11 < %s 2>&1 | FileCheck %s -check-prefix=X11
+; RUN: llc -mtriple=riscv32 <%s
+; RUN: llc -mtriple=riscv64 <%s
+
+; This tests combinations when we would expect an error to be produced because
+; a reserved register is required by the default ABI. The final test checks no
+; errors are produced when no registers are reserved.
+
+define i32 @caller(i32 %a) #0 {
+; X1: in function caller {{.*}} Return address register required, but has been reserved.
+; X2: in function caller {{.*}} Stack pointer required, but has been reserved.
+; X8: in function caller {{.*}} Frame pointer required, but has been reserved.
+; X10: in function caller {{.*}} Argument register required, but has been reserved.
+; X10: in function caller {{.*}} Return value register required, but has been reserved.
+  %call = call i32 @callee(i32 0)
+  ret i32 %call
+}
+
+declare i32 @callee(i32 %a)
+
+define void @clobber() {
+; X11: warning: inline asm clobber list contains reserved registers: X11
+  call void asm sideeffect "nop", "~{x11}"()
+  ret void
+}
+
+attributes #0 = { "frame-pointer"="all" }

diff --git a/llvm/test/CodeGen/RISCV/reserved-regs.ll b/llvm/test/CodeGen/RISCV/reserved-regs.ll
new file mode 100644 (file)
index 0000000..a4d0990
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/reserved-regs.ll
@@ -0,0 +1,130 @@
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x3 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X3
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x3 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X3
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x4 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X4
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x4 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X4
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x5 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X5
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x5 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X5
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x6 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X6
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x6 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X6
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x7 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X7
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x7 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X7
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x8 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X8
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x8 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X8
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x9 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X9
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x9 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X9
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x10 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X10
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x10 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X10
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x11 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X11
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x11 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X11
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x12 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X12
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x12 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X12
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x13 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X13
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x13 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X13
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x14 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X14
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x14 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X14
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x15 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X15
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x15 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X15
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x16 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X16
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x16 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X16
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x17 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X17
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x17 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X17
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x18 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X18
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x18 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X18
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x19 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X19
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x19 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X19
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x20 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X20
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x20 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X20
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x21 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X21
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x21 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X21
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x22 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X22
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x22 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X22
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x23 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X23
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x23 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X23
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x24 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X24
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x24 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X24
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x25 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X25
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x25 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X25
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x26 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X26
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x26 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X26
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x27 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X27
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x27 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X27
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x28 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X28
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x28 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X28
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x29 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X29
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x29 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X29
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x30 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X30
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x30 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X30
+; RUN: llc -mtriple=riscv32 -mattr=+reserve-x31 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X31
+; RUN: llc -mtriple=riscv64 -mattr=+reserve-x31 -verify-machineinstrs < %s | FileCheck %s -check-prefix=X31
+
+; This program is free to use all registers, but needs a stack pointer for
+; spill values, so do not test for reserving the stack pointer.
+
+; Used to exhaust all registers
+@var = global [32 x i64] zeroinitializer
+
+define void @foo() {
+  %1 = load volatile [32 x i64], [32 x i64]* @var
+  store volatile [32 x i64] %1, [32 x i64]* @var
+
+; X3-NOT: lw gp,
+; X3-NOT: ld gp,
+; X4-NOT: lw tp,
+; X4-NOT: ld tp,
+; X5-NOT: lw t0,
+; X5-NOT: ld t0,
+; X6-NOT: lw t1,
+; X6-NOT: ld t1,
+; X7-NOT: lw t2,
+; X7-NOT: ld t2,
+; X8-NOT: lw s0,
+; X8-NOT: ld s0,
+; X9-NOT: lw s1,
+; X9-NOT: ld s1,
+; X10-NOT: lw a0,
+; X10-NOT: ld a0,
+; X11-NOT: lw a1,
+; X11-NOT: ld a1,
+; X12-NOT: lw a2,
+; X12-NOT: ld a2,
+; X13-NOT: lw a3,
+; X13-NOT: ld a3,
+; X14-NOT: lw a4,
+; X14-NOT: ld a4,
+; X15-NOT: lw a5,
+; X15-NOT: ld a5,
+; X16-NOT: lw a6,
+; X16-NOT: ld a6,
+; X17-NOT: lw a7,
+; X17-NOT: ld a7,
+; X18-NOT: lw s2,
+; X18-NOT: ld s2,
+; X19-NOT: lw s3,
+; X19-NOT: ld s3,
+; X20-NOT: lw s4,
+; X20-NOT: ld s4,
+; X21-NOT: lw s5,
+; X21-NOT: ld s5,
+; X22-NOT: lw s6,
+; X22-NOT: ld s6,
+; X23-NOT: lw s7,
+; X23-NOT: ld s7,
+; X24-NOT: lw s8,
+; X24-NOT: ld s8,
+; X25-NOT: lw s9,
+; X25-NOT: ld s9,
+; X26-NOT: lw s10,
+; X26-NOT: ld s10,
+; X27-NOT: lw s11,
+; X27-NOT: ld s11,
+; X28-NOT: lw t3,
+; X28-NOT: ld t3,
+; X29-NOT: lw t4,
+; X29-NOT: ld t4,
+; X30-NOT: lw t5,
+; X30-NOT: ld t5,
+; X31-NOT: lw t6,
+; X31-NOT: ld t6,
+
+  ret void
+}