Merged main:a048ce13e32d into amd-gfx:32c39fafa202

Local branch amd-gfx 32c39fa Merged main:5238e7b302ff into amd-gfx:7da10bfe5304 Remote branch main a048ce1 [X86] Default to -x86-pad-for-align=false to drop assembler difference with or w/o -g
jaebaek · Jan 17, 2021 · f2a7e47 · f2a7e47
2 parents 32c39fa + a048ce1
commit f2a7e47
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Showing 7 changed files with 24 additions and 7 deletions.
diff --git a/llvm/include/llvm/Config/llvm-config.h.cmake b/llvm/include/llvm/Config/llvm-config.h.cmake
@@ -16,7 +16,7 @@
 
 /* Indicate that this is LLVM compiled from the amd-gfx branch. */
 #define LLVM_HAVE_BRANCH_AMD_GFX
-#define LLVM_MAIN_REVISION 377222
+#define LLVM_MAIN_REVISION 377223
 
 /* Define if LLVM_ENABLE_DUMP is enabled */
 #cmakedefine LLVM_ENABLE_DUMP

diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
@@ -109,7 +109,7 @@ cl::opt<unsigned> X86PadMaxPrefixSize(
     cl::desc("Maximum number of prefixes to use for padding"));
 
 cl::opt<bool> X86PadForAlign(
-    "x86-pad-for-align", cl::init(true), cl::Hidden,
+    "x86-pad-for-align", cl::init(false), cl::Hidden,
     cl::desc("Pad previous instructions to implement align directives"));
 
 cl::opt<bool> X86PadForBranchAlign(
@@ -957,6 +957,9 @@ void X86AsmBackend::finishLayout(MCAssembler const &Asm,
   if (!X86PadForAlign && !X86PadForBranchAlign)
     return;
 
+  // The processed regions are delimitered by LabeledFragments. -g may have more
+  // MCSymbols and therefore different relaxation results. X86PadForAlign is
+  // disabled by default to eliminate the -g vs non -g difference.
   DenseSet<MCFragment *> LabeledFragments;
   for (const MCSymbol &S : Asm.symbols())
     LabeledFragments.insert(S.getFragment(false));

diff --git a/llvm/test/MC/X86/align-via-padding-corner.s b/llvm/test/MC/X86/align-via-padding-corner.s
@@ -1,4 +1,4 @@
-  # RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu %s -x86-pad-max-prefix-size=5 | llvm-objdump -d - | FileCheck %s
+  # RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu %s -x86-pad-max-prefix-size=5 -x86-pad-for-align=1 | llvm-objdump -d - | FileCheck %s
 
 
   # The first test check the correctness cornercase - can't add prefixes on a

diff --git a/llvm/test/MC/X86/align-via-padding.s b/llvm/test/MC/X86/align-via-padding.s
@@ -1,4 +1,4 @@
-# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu %s -x86-pad-max-prefix-size=5 | llvm-objdump -d --section=.text - | FileCheck %s
+# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu %s -x86-pad-max-prefix-size=5 -x86-pad-for-align=1 | llvm-objdump -d - | FileCheck %s
 
 # This test file highlights the interactions between prefix padding and
 # relaxation padding.

diff --git a/llvm/test/MC/X86/align-via-relaxation.s b/llvm/test/MC/X86/align-via-relaxation.s
@@ -1,11 +1,25 @@
-# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu -x86-pad-max-prefix-size=0 %s | llvm-objdump -d --section=.text - | FileCheck %s
+# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu -x86-pad-max-prefix-size=0 %s | llvm-objdump -d - | FileCheck %s --check-prefix=NOPAD
+# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu -x86-pad-max-prefix-size=0 -x86-pad-for-align=1 %s | llvm-objdump -d - | FileCheck %s
 
 # This test exercises only the padding via relaxation logic.  The  interaction
 # etween prefix padding and relaxation logic can be seen in align-via-padding.s
 
   .file "test.c"
   .text
   .section  .text
+
+# NOPAD-LABEL: <.text>:
+# NOPAD-NEXT:     0: eb 1f           jmp 0x21 <foo>
+# NOPAD-NEXT:     2: eb 1d           jmp 0x21 <foo>
+# NOPAD-NEXT:     4: eb 1b           jmp 0x21 <foo>
+# NOPAD-NEXT:     6: eb 19           jmp 0x21 <foo>
+# NOPAD-NEXT:     8: eb 17           jmp 0x21 <foo>
+# NOPAD-NEXT:     a: eb 15           jmp 0x21 <foo>
+# NOPAD-NEXT:     c: eb 13           jmp 0x21 <foo>
+# NOPAD-NEXT:     e: 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00  nopw    %cs:(%rax,%rax)
+# NOPAD-NEXT:    1d: 0f 1f 00        nopl (%rax)
+# NOPAD-NEXT:    20: cc              int3
+
   # Demonstrate that we can relax instructions to provide padding, not
   # just insert nops.  jmps are being used for ease of demonstration.
   # CHECK: .text

diff --git a/llvm/test/MC/X86/prefix-padding-32.s b/llvm/test/MC/X86/prefix-padding-32.s
@@ -1,4 +1,4 @@
-# RUN: llvm-mc -filetype=obj -triple i386-pc-linux-gnu %s -x86-pad-max-prefix-size=15 | llvm-objdump -d --section=.text - | FileCheck %s
+# RUN: llvm-mc -filetype=obj -triple i386-pc-linux-gnu %s -x86-pad-max-prefix-size=15 -x86-pad-for-align=1 | llvm-objdump -d - | FileCheck %s
 
 # Check prefix padding generation for all cases on 32 bit x86.
 

diff --git a/llvm/test/MC/X86/prefix-padding-64.s b/llvm/test/MC/X86/prefix-padding-64.s
@@ -1,4 +1,4 @@
-# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu %s -x86-pad-max-prefix-size=15 | llvm-objdump -d --section=.text - | FileCheck %s
+# RUN: llvm-mc -mcpu=skylake -filetype=obj -triple x86_64-pc-linux-gnu %s -x86-pad-max-prefix-size=15 -x86-pad-for-align=1 | llvm-objdump -d - | FileCheck %s
 
 # Check prefix padding generation for all cases on 64 bit x86.