[PPC64] Fix toc restore nops offset for V2 ABI

The PPC64 V2 ABI restores the toc base by loading from an offset of 24 from r1.
This patch fixes the offset and updates the testcases from V1 to V2. It also
issues an error when a nop is missing after a call to an external function.

Differential Revision: https://reviews.llvm.org/D45892

llvm-svn: 330600

diff --git a/lld/ELF/InputSection.cpp b/lld/ELF/InputSection.cpp
index 4604253..dfe8f50 100644 (file)
--- a/lld/ELF/InputSection.cpp
+++ b/lld/ELF/InputSection.cpp
@@ -740,8 +740,12 @@ void InputSectionBase::relocateAlloc(uint8_t *Buf, uint8_t *BufEnd) {
       break;
     case R_PPC_PLT_OPD:
       // Patch a nop (0x60000000) to a ld.
-      if (BufLoc + 8 <= BufEnd && read32be(BufLoc + 4) == 0x60000000)
-        write32be(BufLoc + 4, 0xe8410028); // ld %r2, 40(%r1)
+      if (BufLoc + 8 <= BufEnd && read32(BufLoc + 4) == 0x60000000) {
+        write32(BufLoc + 4, 0xe8410018); // ld %r2, 24(%r1)
+      } else {
+        error(getErrorLocation(BufLoc) + "error: call lacks nop, can't restore toc.");
+        return;
+      }
       LLVM_FALLTHROUGH;
     default:
       Target->relocateOne(BufLoc, Type, TargetVA);

diff --git a/lld/test/ELF/Inputs/ppc64-func.s b/lld/test/ELF/Inputs/ppc64-func.s
new file mode 100644 (file)
index 0000000..745faf8
--- /dev/null
+++ b/lld/test/ELF/Inputs/ppc64-func.s
@@ -0,0 +1,14 @@
+    .text
+    .abiversion 2
+    .globl  foo_not_shared
+    .p2align        4
+    .type   foo_not_shared,@function
+
+foo_not_shared:
+.Lfunc_begin0:
+  li 3, 55
+  blr
+  .long   0
+  .quad   0
+.Lfunc_end0:
+  .size foo_not_shared, .Lfunc_end0-.Lfunc_begin0

diff --git a/lld/test/ELF/ppc64-error-toc-restore.s b/lld/test/ELF/ppc64-error-toc-restore.s
new file mode 100644 (file)
index 0000000..d9adbd8
--- /dev/null
+++ b/lld/test/ELF/ppc64-error-toc-restore.s
@@ -0,0 +1,14 @@
+// RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
+// RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %p/Inputs/shared-ppc64le.s -o %t2.o
+// RUN: ld.lld -shared %t2.o -o %t2.so
+// RUN: not ld.lld %t.o %t2.so -o %t 2>&1 | FileCheck %s
+// REQUIRES: ppc
+
+# Calling external function bar needs a nop
+// CHECK: error: call lacks nop, can't restore toc
+    .text
+    .abiversion 2
+
+.global _start
+_start:
+  bl foo

diff --git a/lld/test/ELF/ppc64-error-toc-tail-call.s b/lld/test/ELF/ppc64-error-toc-tail-call.s
new file mode 100644 (file)
index 0000000..3c096d3
--- /dev/null
+++ b/lld/test/ELF/ppc64-error-toc-tail-call.s
@@ -0,0 +1,14 @@
+// RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
+// RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %p/Inputs/shared-ppc64le.s -o %t2.o
+// RUN: ld.lld -shared %t2.o -o %t2.so
+// RUN: not ld.lld %t.o %t2.so -o %t 2>&1 | FileCheck %s
+// REQUIRES: ppc
+
+# A tail call to an external function without a nop should issue an error.
+// CHECK: error: call lacks nop, can't restore toc
+    .text
+    .abiversion 2
+
+.global _start
+_start:
+  b foo

diff --git a/lld/test/ELF/ppc64-ifunc.s b/lld/test/ELF/ppc64-ifunc.s
index b993206..797a650 100644 (file)
--- a/lld/test/ELF/ppc64-ifunc.s
+++ b/lld/test/ELF/ppc64-ifunc.s
@@ -1,34 +1,35 @@
 # REQUIRES: ppc
-# RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %s -o %t.o
-# RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %p/Inputs/shared-ppc64.s -o %t2.o
+# RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
+# RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %p/Inputs/shared-ppc64le.s -o %t2.o
 # RUN: ld.lld -shared %t2.o -o %t2.so
 # RUN: ld.lld %t.o %t2.so -o %t
 # RUN: llvm-objdump -d %t | FileCheck %s
 
 # CHECK:      _start:
-# CHECK-NEXT:  10010004: {{.*}} bl .+12
-# CHECK-NEXT:  10010008: {{.*}} bl .+40
+# CHECK-NEXT: 10010004:       1d 00 00 48     bl .+28
+# CHECK-NEXT: 10010008:       18 00 41 e8     ld 2, 24(1)
+# CHECK-NEXT: 1001000c:       35 00 00 48     bl .+52
+# CHECK-NEXT: 10010010:       18 00 41 e8     ld 2, 24(1)
 
-# 0x10010004 + 12 = 0x10010010 (PLT entry 0)
-# 0x10010008 + 40 = 0x10010030 (PLT entry 1)
+# 0x10010004 + 28 = 0x10010020 (PLT entry 0)
+# 0x1001000c + 52 = 0x10010040 (PLT entry 1)
 
 # CHECK:     Disassembly of section .plt:
-# CHECK:       10010010: {{.*}} std 2, 40(1)
-# CHECK-NEXT:  10010014: {{.*}} addis 11, 2, 4098
-# CHECK-NEXT:  10010018: {{.*}} ld 12, -32744(11)
-# CHECK-NEXT:  1001001c: {{.*}} ld 11, 0(12)
-# CHECK-NEXT:  10010020: {{.*}} mtctr 11
-# CHECK-NEXT:  10010024: {{.*}} ld 2, 8(12)
-# CHECK-NEXT:  10010028: {{.*}} ld 11, 16(12)
-# CHECK-NEXT:  1001002c: {{.*}} bctr
-# CHECK-NEXT:  10010030: {{.*}} std 2, 40(1)
-# CHECK-NEXT:  10010034: {{.*}} addis 11, 2, 4098
-# CHECK-NEXT:  10010038: {{.*}} ld 12, -32736(11)
-# CHECK-NEXT:  1001003c: {{.*}} ld 11, 0(12)
-# CHECK-NEXT:  10010040: {{.*}} mtctr 11
-# CHECK-NEXT:  10010044: {{.*}} ld 2, 8(12)
-# CHECK-NEXT:  10010048: {{.*}} ld 11, 16(12)
-# CHECK-NEXT:  1001004c: {{.*}} bctr
+# CHECK-NEXT: .plt:
+# CHECK-NEXT: 10010020:       18 00 41 f8     std 2, 24(1)
+# CHECK-NEXT: 10010024:       02 10 82 3d     addis 12, 2, 4098
+# CHECK-NEXT: 10010028:       10 80 8c e9     ld 12, -32752(12)
+# CHECK-NEXT: 1001002c:       a6 03 89 7d     mtctr 12
+# CHECK-NEXT: 10010030:       20 04 80 4e     bctr
+# CHECK-NEXT: 10010034:       08 00 e0 7f     trap
+# CHECK-NEXT: 10010038:       08 00 e0 7f     trap
+# CHECK-NEXT: 1001003c:       08 00 e0 7f     trap
+# CHECK-NEXT: 10010040:       18 00 41 f8     std 2, 24(1)
+# CHECK-NEXT: 10010044:       02 10 82 3d     addis 12, 2, 4098
+# CHECK-NEXT: 10010048:       18 80 8c e9     ld 12, -32744(12)
+# CHECK-NEXT: 1001004c:       a6 03 89 7d     mtctr 12
+    .text
+    .abiversion 2
 
 .type ifunc STT_GNU_IFUNC
 .globl ifunc
@@ -37,5 +38,7 @@ ifunc:
 
 .global _start
 _start:
-  bl bar
+  bl foo
+  nop
   bl ifunc
+  nop

diff --git a/lld/test/ELF/ppc64-toc-restore.s b/lld/test/ELF/ppc64-toc-restore.s
index 0c3d30b..f0ef8d3 100644 (file)
--- a/lld/test/ELF/ppc64-toc-restore.s
+++ b/lld/test/ELF/ppc64-toc-restore.s
@@ -1,62 +1,69 @@
-// RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %s -o %t.o
-// RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %p/Inputs/shared-ppc64.s -o %t2.o
+// RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
+// RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %p/Inputs/shared-ppc64le.s -o %t2.o
+// RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %p/Inputs/ppc64-func.s -o %t3.o
 // RUN: ld.lld -shared %t2.o -o %t2.so
-// RUN: ld.lld %t.o %t2.so -o %t
+// RUN: ld.lld %t.o %t2.so %t3.o -o %t
 // RUN: llvm-objdump -d %t | FileCheck %s
 // REQUIRES: ppc
+    .text
+    .abiversion 2
+.global bar_local
+bar_local:
+  li 3, 2
+  blr
 
+# Calling external function foo in a shared object needs a nop.
+# Calling local function bar_local doe snot need a nop.
 // CHECK: Disassembly of section .text:
-
 .global _start
 _start:
-  bl bar
+  bl foo
   nop
+  bl bar_local
 
 // CHECK: _start:
-// CHECK: 10010000:       48 00 00 21     bl .+32
-// CHECK-NOT: 10010004:       60 00 00 00     nop
-// CHECK: 10010004:       e8 41 00 28     ld 2, 40(1)
-
-.global noret
-noret:
-  bl bar
-  li 5, 7
-
-// CHECK: noret:
-// CHECK: 10010008: 48 00 00 19 bl .+24
-// CHECK: 1001000c: 38 a0 00 07 li 5, 7
+// CHECK: 10010008:       49 00 00 48     bl .+72
+// CHECK-NOT: 1001000c:       00 00 00 60     nop
+// CHECK: 1001000c:       18 00 41 e8     ld 2, 24(1)
+// CHECK: 10010010:       f1 ff ff 4b     bl .+67108848
+// CHECK-NOT: 10010014:       00 00 00 60     nop
+// CHECK-NOT: 10010014:       18 00 41 e8     ld 2, 24(1)
 
-.global noretend
-noretend:
-  bl bar
-
-// CHECK: noretend:
-// CHECK: 10010010: 48 00 00 11 bl .+16
+# Calling a function in another object file which will have same
+# TOC base does not need a nop. If nop present, do not rewrite to
+# a toc restore
+.global diff_object
+_diff_object:
+  bl foo_not_shared
+  bl foo_not_shared
+  nop
 
-.global noretb
-noretb:
-  b bar
+// CHECK: _diff_object:
+// CHECK-NEXT: 10010014:       1d 00 00 48     bl .+28
+// CHECK-NEXT: 10010018:       19 00 00 48     bl .+24
+// CHECK-NEXT: 1001001c:       00 00 00 60     nop
 
-// CHECK: noretb:
-// CHECK: 10010014: 48 00 00 0c b .+12
+# Branching to a local function does not need a nop
+.global noretbranch
+noretbranch:
+  b bar_local
+// CHECK: noretbranch:
+// CHECK: 10010020:       e0 ff ff 4b     b .+67108832
+// CHECK-NOT: 10010024:       00 00 00 60     nop
+// CHECK-NOT: 10010024:       18 00 41 e8     ld 2, 24(1)
 
 // This should come last to check the end-of-buffer condition.
 .global last
 last:
-  bl bar
+  bl foo
   nop
-
 // CHECK: last:
-// CHECK: 10010018: 48 00 00 09 bl .+8
-// CHECK: 1001001c: e8 41 00 28 ld 2, 40(1)
+// CHECK: 10010024:       2d 00 00 48     bl .+44
+// CHECK-NEXT: 10010028:       18 00 41 e8     ld 2, 24(1)
 
 // CHECK: Disassembly of section .plt:
 // CHECK: .plt:
-// CHECK: 10010020:       f8 41 00 28     std 2, 40(1)
-// CHECK: 10010024:       3d 62 10 02     addis 11, 2, 4098
-// CHECK: 10010028:       e9 8b 80 18     ld 12, -32744(11)
-// CHECK: 1001002c:       e9 6c 00 00     ld 11, 0(12)
-// CHECK: 10010030:       7d 69 03 a6     mtctr 11
-// CHECK: 10010034:       e8 4c 00 08     ld 2, 8(12)
-// CHECK: 10010038:       e9 6c 00 10     ld 11, 16(12)
-// CHECK: 1001003c:       4e 80 04 20     bctr
+// CHECK-NEXT: 10010050:       18 00 41 f8     std 2, 24(1)
+// CHECK-NEXT: 10010054:       02 10 82 3d     addis 12, 2, 4098
+// CHECK-NEXT: 10010058:       10 80 8c e9     ld 12, -32752(12)
+// CHECK-NEXT: 1001005c:       a6 03 89 7d     mtctr 12

diff --git a/lld/test/ELF/ppc64-weak-undef-call-shared.s b/lld/test/ELF/ppc64-weak-undef-call-shared.s
index 2c27a27..e1ac834 100644 (file)
--- a/lld/test/ELF/ppc64-weak-undef-call-shared.s
+++ b/lld/test/ELF/ppc64-weak-undef-call-shared.s
@@ -10,7 +10,7 @@
 .text
 .Lfoo:
   bl weakfunc
+  nop
 // CHECK-NOT: R_PPC64_REL24
 
 .weak weakfunc
-