[llvm] 11725b5 - [InstCombine] Add tests for incorrect range handling in ctz fold (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2024-06-04T15:48:08+02:00
New Revision: 11725b5240840e077c944af6a56e75dd00275395

URL: https://github.com/llvm/llvm-project/commit/11725b5240840e077c944af6a56e75dd00275395
DIFF: https://github.com/llvm/llvm-project/commit/11725b5240840e077c944af6a56e75dd00275395.diff

LOG: [InstCombine] Add tests for incorrect range handling in ctz fold (NFC)

Added: 
    

Modified: 
    llvm/test/Transforms/InstCombine/select-cmp-cttz-ctlz.ll

Removed: 
    


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diff  --git a/llvm/test/Transforms/InstCombine/select-cmp-cttz-ctlz.ll b/llvm/test/Transforms/InstCombine/select-cmp-cttz-ctlz.ll
index 3d5f2c209edf3..eac46856bb4b5 100644
--- a/llvm/test/Transforms/InstCombine/select-cmp-cttz-ctlz.ll
+++ b/llvm/test/Transforms/InstCombine/select-cmp-cttz-ctlz.ll
@@ -49,6 +49,18 @@ define i16 @test4(i16 %x) {
   ret i16 %cond
 }
 
+; FIXME: This is a miscompile.
+define i16 @test4_with_range(i16 %x) {
+; CHECK-LABEL: @test4_with_range(
+; CHECK-NEXT:    [[CT:%.*]] = call range(i16 0, 16) i16 @llvm.ctlz.i16(i16 [[X:%.*]], i1 false)
+; CHECK-NEXT:    ret i16 [[CT]]
+;
+  %ct = call range(i16 0, 16) i16 @llvm.ctlz.i16(i16 %x, i1 true)
+  %tobool = icmp eq i16 %x, 0
+  %cond = select i1 %tobool, i16 16, i16 %ct
+  ret i16 %cond
+}
+
 define i32 @test5(i32 %x) {
 ; CHECK-LABEL: @test5(
 ; CHECK-NEXT:    [[CT:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 false)
@@ -115,6 +127,18 @@ define i16 @test4b(i16 %x) {
   ret i16 %cond
 }
 
+; FIXME: This is a miscompile.
+define i16 @test4b_with_range(i16 %x) {
+; CHECK-LABEL: @test4b_with_range(
+; CHECK-NEXT:    [[CT:%.*]] = call range(i16 0, 16) i16 @llvm.cttz.i16(i16 [[X:%.*]], i1 false)
+; CHECK-NEXT:    ret i16 [[CT]]
+;
+  %ct = call range(i16 0, 16) i16 @llvm.cttz.i16(i16 %x, i1 true)
+  %tobool = icmp eq i16 %x, 0
+  %cond = select i1 %tobool, i16 16, i16 %ct
+  ret i16 %cond
+}
+
 define i32 @test5b(i32 %x) {
 ; CHECK-LABEL: @test5b(
 ; CHECK-NEXT:  entry: