[llvm] r356550 - [ExpandMemCmp] Trigger on bcmp too.

[Clement Courbet via llvm-commits]

Author: courbet
Date: Wed Mar 20 04:51:11 2019
New Revision: 356550

URL: http://llvm.org/viewvc/llvm-project?rev=356550&view=rev
Log:
[ExpandMemCmp] Trigger on bcmp too.

Summary: Fixes 41150.

Reviewers: gchatelet

Subscribers: hiraditya, llvm-commits, ckennelly, sbenza, jyknight

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59593

Modified:
    llvm/trunk/lib/CodeGen/ExpandMemCmp.cpp
    llvm/trunk/test/CodeGen/X86/memcmp-optsize.ll

Modified: llvm/trunk/lib/CodeGen/ExpandMemCmp.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ExpandMemCmp.cpp?rev=356550&r1=356549&r2=356550&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ExpandMemCmp.cpp (original)
+++ llvm/trunk/lib/CodeGen/ExpandMemCmp.cpp Wed Mar 20 04:51:11 2019
@@ -823,7 +823,8 @@ bool ExpandMemCmpPass::runOnBlock(
     }
     LibFunc Func;
     if (TLI->getLibFunc(ImmutableCallSite(CI), Func) &&
-        Func == LibFunc_memcmp && expandMemCmp(CI, TTI, TL, &DL)) {
+        (Func == LibFunc_memcmp || Func == LibFunc_bcmp) &&
+        expandMemCmp(CI, TTI, TL, &DL)) {
       return true;
     }
   }

Modified: llvm/trunk/test/CodeGen/X86/memcmp-optsize.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/memcmp-optsize.ll?rev=356550&r1=356549&r2=356550&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/memcmp-optsize.ll (original)
+++ llvm/trunk/test/CodeGen/X86/memcmp-optsize.ll Wed Mar 20 04:51:11 2019
@@ -10,6 +10,7 @@
 @.str = private constant [65 x i8] c"0123456789012345678901234567890123456789012345678901234567890123\00", align 1
 
 declare i32 @memcmp(i8*, i8*, i64)
+declare i32 @bcmp(i8*, i8*, i64)
 
 define i32 @length2(i8* %X, i8* %Y) nounwind optsize {
 ; X86-LABEL: length2:
@@ -982,3 +983,31 @@ define i1 @length64_eq_const(i8* %X) nou
   ret i1 %c
 }
 
+define i32 @bcmp_length2(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: bcmp_length2:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movzwl (%ecx), %ecx
+; X86-NEXT:    movzwl (%eax), %edx
+; X86-NEXT:    rolw $8, %cx
+; X86-NEXT:    rolw $8, %dx
+; X86-NEXT:    movzwl %cx, %eax
+; X86-NEXT:    movzwl %dx, %ecx
+; X86-NEXT:    subl %ecx, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: bcmp_length2:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    movzwl (%rsi), %ecx
+; X64-NEXT:    rolw $8, %ax
+; X64-NEXT:    rolw $8, %cx
+; X64-NEXT:    movzwl %ax, %eax
+; X64-NEXT:    movzwl %cx, %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @bcmp(i8* %X, i8* %Y, i64 2) nounwind
+  ret i32 %m
+}
+