[llvm-branch-commits] [llvm] 7421cbd - [InstCombine][Test] Test for fix of replacing select with Phis when branch has the same labels

[Hans Wennborg via llvm-branch-commits]

Author: Max Kazantsev
Date: 2020-07-20T15:28:01+02:00
New Revision: 7421cbd7a5a74b48a173f60763b9b78ecd3aec09

URL: https://github.com/llvm/llvm-project/commit/7421cbd7a5a74b48a173f60763b9b78ecd3aec09
DIFF: https://github.com/llvm/llvm-project/commit/7421cbd7a5a74b48a173f60763b9b78ecd3aec09.diff

LOG: [InstCombine][Test] Test for fix of replacing select with Phis when branch has the same labels

An additional test that allows to check the correctness of handling the case of the same
branch labels in the dominator when trying to replace select with phi-node.

Patch By: Kirill Polushin
Differential Revision: https://reviews.llvm.org/D84006
Reviewed By: mkazantsev

(cherry picked from commit df6e185e8f895686510117301e568e5043909b66)

Added: 
    

Modified: 
    llvm/test/Transforms/InstCombine/select.ll

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/InstCombine/select.ll b/llvm/test/Transforms/InstCombine/select.ll
index 8cd0e35139a8..185ff838b819 100644
--- a/llvm/test/Transforms/InstCombine/select.ll
+++ b/llvm/test/Transforms/InstCombine/select.ll
@@ -2000,6 +2000,21 @@ merge:
   ret i32 %s
 }
 
+define i32 @select_dominating_cond_same_labels(i1 %cond) {
+; CHECK-LABEL: @select_dominating_cond_same_labels(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br i1 false, label [[EXIT:%.*]], label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[RESULT:%.*]] = select i1 [[COND:%.*]], i32 123, i32 456
+; CHECK-NEXT:    ret i32 [[RESULT]]
+;
+entry:
+  %result = select i1 %cond, i32 123, i32 456
+  br i1 %cond, label %exit, label %exit
+exit:
+  ret i32 %result
+}
+
 define i32 @select_phi_same_condition(i1 %cond, i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @select_phi_same_condition(
 ; CHECK-NEXT:  entry: