When performing a conditional branch depending on the value of a comparison
%cmp (eg: A==B) we already replace %cmp with "true" under the true edge, and
with "false" under the false edge. This change enhances this to replace the
negated compare (A!=B) with "false" under the true edge and "true" under the
false edge. Reported to improve perlbench results by 1%.
llvm-svn: 151517
diff --git a/llvm/test/Transforms/GVN/condprop.ll b/llvm/test/Transforms/GVN/condprop.ll
index c17c994..97a0d31 100644
--- a/llvm/test/Transforms/GVN/condprop.ll
+++ b/llvm/test/Transforms/GVN/condprop.ll
@@ -111,3 +111,67 @@
; CHECK: call void @bar(i32 %x)
ret void
}
+
+; CHECK: @test5
+define i1 @test5(i32 %x, i32 %y) {
+ %cmp = icmp eq i32 %x, %y
+ br i1 %cmp, label %same, label %different
+
+same:
+ %cmp2 = icmp ne i32 %x, %y
+; CHECK: ret i1 false
+ ret i1 %cmp2
+
+different:
+ %cmp3 = icmp eq i32 %x, %y
+; CHECK: ret i1 false
+ ret i1 %cmp3
+}
+
+; CHECK: @test6
+define i1 @test6(i32 %x, i32 %y) {
+ %cmp2 = icmp ne i32 %x, %y
+ %cmp = icmp eq i32 %x, %y
+ %cmp3 = icmp eq i32 %x, %y
+ br i1 %cmp, label %same, label %different
+
+same:
+; CHECK: ret i1 false
+ ret i1 %cmp2
+
+different:
+; CHECK: ret i1 false
+ ret i1 %cmp3
+}
+
+; CHECK: @test7
+define i1 @test7(i32 %x, i32 %y) {
+ %cmp = icmp sgt i32 %x, %y
+ br i1 %cmp, label %same, label %different
+
+same:
+ %cmp2 = icmp sle i32 %x, %y
+; CHECK: ret i1 false
+ ret i1 %cmp2
+
+different:
+ %cmp3 = icmp sgt i32 %x, %y
+; CHECK: ret i1 false
+ ret i1 %cmp3
+}
+
+; CHECK: @test8
+define i1 @test8(i32 %x, i32 %y) {
+ %cmp2 = icmp sle i32 %x, %y
+ %cmp = icmp sgt i32 %x, %y
+ %cmp3 = icmp sgt i32 %x, %y
+ br i1 %cmp, label %same, label %different
+
+same:
+; CHECK: ret i1 false
+ ret i1 %cmp2
+
+different:
+; CHECK: ret i1 false
+ ret i1 %cmp3
+}