Revert "[AArch64][AsmParser] Remove 'x31' alias for 'sp/xzr' register."

This reverts commit 8b281bfaf35d00d42c2993fd5a80d749cc21f45e.

diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index af5075e..a511749 100644 (file)
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -90,15 +90,6 @@ Changes to the ARM Backend
 
 During this release ...
 
-Changes to the AArch64 Backend
-------------------------------
-
-During this release ...
-
-* The assembler no longer accepts ``w31`` and ``x31`` as aliases for ``wzr``
-  and ``xzr``, because the architecture manual explicitly states that no
-  registers with those names exist.
-
 Changes to the MIPS Target
 --------------------------
 

diff --git a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
index 080a2c5..ae95d54 100644 (file)
--- a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
+++ b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
@@ -2322,6 +2322,8 @@ unsigned AArch64AsmParser::matchRegisterNameAlias(StringRef Name,
     if (auto RegNum = StringSwitch<unsigned>(Name.lower())
                     .Case("fp", AArch64::FP)
                     .Case("lr",  AArch64::LR)
+                    .Case("x31", AArch64::XZR)
+                    .Case("w31", AArch64::WZR)
                     .Default(0))
       return Kind == RegKind::Scalar ? RegNum : 0;
 

diff --git a/llvm/test/MC/AArch64/basic-a64-diagnostics.s b/llvm/test/MC/AArch64/basic-a64-diagnostics.s
index f910fd9..9114d30 100644 (file)
--- a/llvm/test/MC/AArch64/basic-a64-diagnostics.s
+++ b/llvm/test/MC/AArch64/basic-a64-diagnostics.s
@@ -2443,38 +2443,30 @@
 //// 32-bit addresses
         ldr w0, [w20]
         ldrsh x3, [wsp]
-        ldrb   w0, [sp, x31]
 // CHECK-ERROR: error: invalid operand for instruction
 // CHECK-ERROR-NEXT:         ldr w0, [w20]
 // CHECK-ERROR-NEXT:                  ^
 // CHECK-ERROR-NEXT: error: invalid operand for instruction
 // CHECK-ERROR-NEXT:         ldrsh x3, [wsp]
 // CHECK-ERROR-NEXT:                    ^
-// CHECK-ERROR-NEXT: error: index must be an integer in range [-256, 255].
-// CHECK-ERROR-NEXT: ldrb   w0, [sp, x31]
-// CHECK-ERROR-NETX:                 ^
 
 //// Store things
         strb w0, [wsp]
         strh w31, [x23, #1]
         str x5, [x22, #12]
         str w7, [x12, #16384]
-        strb   w0, [sp, x31]
 // CHECK-ERROR: error: invalid operand for instruction
 // CHECK-ERROR-NEXT: strb w0, [wsp]
 // CHECK-ERROR-NEXT:           ^
-// CHECK-ERROR: error: invalid operand for instruction
-// CHECK-ERROR-NEXT:         strh w31, [x23, #1]
-// CHECK-ERROR-NEXT:              ^
+// CHECK-ERROR-AARCH64: error: invalid operand for instruction
+// CHECK-ERROR-AARCH64-NEXT:         strh w31, [x23, #1]
+// CHECK-ERROR-AARCH64-NEXT:              ^
 // CHECK-ERROR-AARCH64-NEXT: error: too few operands for instruction
 // CHECK-ERROR-AARCH64-NEXT:         str x5, [x22, #12]
 // CHECK-ERROR-AARCH64-NEXT:                 ^
 // CHECK-ERROR-NEXT: error: {{expected|index must be an}} integer in range [-256, 255]
 // CHECK-ERROR-NEXT:         str w7, [x12, #16384]
 // CHECK-ERROR-NEXT:                 ^
-// CHECK-ERROR-NEXT: error: index must be an integer in range [-256, 255].
-// CHECK-ERROR-NEXT: strb   w0, [sp, x31]
-// CHECK-ERROR-NEXT:                 ^
 
 //// Bad PRFMs
         prfm #-1, [sp]

diff --git a/llvm/test/tools/llvm-mca/AArch64/Exynos/load.s b/llvm/test/tools/llvm-mca/AArch64/Exynos/load.s
index ca02708..2e90e5a 100644 (file)
--- a/llvm/test/tools/llvm-mca/AArch64/Exynos/load.s
+++ b/llvm/test/tools/llvm-mca/AArch64/Exynos/load.s
@@ -8,10 +8,10 @@ ldur  x0, [sp, #8]
 ldrb   w0, [sp], #1
 ldrsh  w0, [sp, #2]!
 ldr    x0, [sp, #8]
-ldrb   w0, [sp, xzr]
-ldrsh  w0, [sp, xzr, lsl #1]
-ldr    w0, [sp, wzr, sxtw]
-ldr    x0, [sp, wzr, uxtw #3]
+ldrb   w0, [sp, x31]
+ldrsh  w0, [sp, x31, lsl #1]
+ldr    w0, [sp, w31, sxtw]
+ldr    x0, [sp, w31, uxtw #3]
 ldnp   w0, w1, [sp, #8]
 ldp    x0, x1, [sp], #16
 ldpsw  x0, x1, [sp, #8]!

diff --git a/llvm/test/tools/llvm-mca/AArch64/Exynos/store.s b/llvm/test/tools/llvm-mca/AArch64/Exynos/store.s
index 7729b05..3c7d412 100644 (file)
--- a/llvm/test/tools/llvm-mca/AArch64/Exynos/store.s
+++ b/llvm/test/tools/llvm-mca/AArch64/Exynos/store.s
@@ -7,10 +7,10 @@ stur  x0, [sp, #8]
 strb   w0, [sp], #1
 strh   w0, [sp, #2]!
 str    x0, [sp, #8]
-strb   w0, [sp, xzr]
-strh   w0, [sp, xzr, lsl #1]
-str    w0, [sp, wzr, sxtw]
-str    x0, [sp, wzr, uxtw #3]
+strb   w0, [sp, x31]
+strh   w0, [sp, x31, lsl #1]
+str    w0, [sp, w31, sxtw]
+str    x0, [sp, w31, uxtw #3]
 stnp   w0, w1, [sp, #8]
 stp    x0, x1, [sp], #16
 stp    w0, w1, [sp, #8]!