The X86 backend has a number of optimizations for SETCC nodes which use

arithmetic instructions. However, when small data types are used, a truncate
node appears between the SETCC node and the arithmetic operation. This patch
adds support for this pattern.

Before:
  xorl  %esi, %edi
  testb %dil, %dil
  setne %al
  ret

After:
  xorb  %dil, %sil
  setne %al
  ret

rdar://12081007



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162160 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 45 insertions, 0 deletions

diff --git a/test/CodeGen/X86/2012-08-16-setcc.ll b/test/CodeGen/X86/2012-08-16-setcc.ll
new file mode 100644
index 0000000000..ed511567c3
--- /dev/null
+++ b/test/CodeGen/X86/2012-08-16-setcc.ll
@@ -0,0 +1,45 @@
+; RUN: llc < %s -mtriple=x86_64-apple-macosx | FileCheck %s
+
+; rdar://12081007
+
+; CHECK: and_1:
+; CHECK: andb
+; CHECK-NEXT: cmovnel
+; CHECK: ret
+define i32 @and_1(i8 zeroext %a, i8 zeroext %b, i32 %x) {
+  %1 = and i8 %b, %a
+  %2 = icmp ne i8 %1, 0
+  %3 = select i1 %2, i32 %x, i32 0
+  ret i32 %3
+}
+
+; CHECK: and_2:
+; CHECK: andb
+; CHECK-NEXT: setne
+; CHECK: ret
+define zeroext i1 @and_2(i8 zeroext %a, i8 zeroext %b) {
+  %1 = and i8 %b, %a
+  %2 = icmp ne i8 %1, 0
+  ret i1 %2
+}
+
+; CHECK: xor_1:
+; CHECK: xorb
+; CHECK-NEXT: cmovnel
+; CHECK: ret
+define i32 @xor_1(i8 zeroext %a, i8 zeroext %b, i32 %x) {
+  %1 = xor i8 %b, %a
+  %2 = icmp ne i8 %1, 0
+  %3 = select i1 %2, i32 %x, i32 0
+  ret i32 %3
+}
+
+; CHECK: xor_2:
+; CHECK: xorb
+; CHECK-NEXT: setne
+; CHECK: ret
+define zeroext i1 @xor_2(i8 zeroext %a, i8 zeroext %b) {
+  %1 = xor i8 %b, %a
+  %2 = icmp ne i8 %1, 0
+  ret i1 %2
+}