[llvm] r348853 - Fix not correct imm operand assertion for SUB32ri in X86CondBrFolding::analyzeCompare

[Craig Topper via llvm-commits]

Author: ctopper
Date: Tue Dec 11 07:32:14 2018
New Revision: 348853

URL: http://llvm.org/viewvc/llvm-project?rev=348853&view=rev
Log:
Fix not correct imm operand assertion for SUB32ri in X86CondBrFolding::analyzeCompare

Summary:
When doing X86CondBrFolding::analyzeCompare, it will meet the SUB32ri instruction as below to use the global address for its operand,
  %733:gr32 = SUB32ri %62:gr32(tied-def 0), @img2buf_normal, implicit-def $eflags
  JNE_1 %bb.41, implicit $eflags

so the assertion "assert(MI.getOperand(ValueIndex).isImm() && "Expecting Imm operand")" is not correct and change the assert to if make X86CondBrFolding::analyzeCompare return false as not finding the compare for this

Patch by Jianping Chen

Reviewers: smaslov, LuoYuanke, liutianle, Jianping

Reviewed By: Jianping

Subscribers: lebedev.ri, llvm-commits

Differential Revision: https://reviews.llvm.org/D54250

Added:
    llvm/trunk/test/CodeGen/X86/test_x86condbr_globaladdr.mir
Modified:
    llvm/trunk/lib/Target/X86/X86CondBrFolding.cpp

Modified: llvm/trunk/lib/Target/X86/X86CondBrFolding.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86CondBrFolding.cpp?rev=348853&r1=348852&r2=348853&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86CondBrFolding.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86CondBrFolding.cpp Tue Dec 11 07:32:14 2018
@@ -468,7 +468,8 @@ bool X86CondBrFolding::analyzeCompare(co
     break;
   }
   SrcReg = MI.getOperand(SrcRegIndex).getReg();
-  assert(MI.getOperand(ValueIndex).isImm() && "Expecting Imm operand");
+  if (!MI.getOperand(ValueIndex).isImm())
+    return false;
   CmpValue = MI.getOperand(ValueIndex).getImm();
   return true;
 }

Added: llvm/trunk/test/CodeGen/X86/test_x86condbr_globaladdr.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/test_x86condbr_globaladdr.mir?rev=348853&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/test_x86condbr_globaladdr.mir (added)
+++ llvm/trunk/test/CodeGen/X86/test_x86condbr_globaladdr.mir Tue Dec 11 07:32:14 2018
@@ -0,0 +1,30 @@
+# RUN: llc -o - %s -mtriple=i686-- -mcpu=ivybridge --run-pass X86CondBrFolding | FileCheck %s
+
+# Test wrong assertion when meet SUB32ri with global address
+# in X86CondBrFoldingiPass
+--- |
+  @img2buf_normal = external global i32
+  define void @func() { ret void }
+...
+---
+# CHECK: bb.0:
+# CHECK: %2:gr32 = SUB32ri %1, @img2buf_normal, implicit-def $eflags
+
+name: func
+tracksRegLiveness: true
+body: |
+  bb.0:
+    liveins: $edx
+    %1:gr32 = COPY $edx
+    %2:gr32 = MOV32rm %1:gr32, 1, $noreg, 850256, $noreg
+    %3:gr32 = SUB32ri %2:gr32, @img2buf_normal, implicit-def $eflags
+    JE_1 %bb.2, implicit $eflags
+    JMP_1 %bb.3
+
+  bb.2:
+    RET 0, undef $eax
+
+  bb.3:
+    $eax = MOV32rr %3:gr32
+    RET 0, $eax
+...