[llvm] 82d7502 - llvm-reduce: Handle nneg flag

[Matt Arsenault via llvm-commits]

Author: Matt Arsenault
Date: 2023-12-13T11:13:09+07:00
New Revision: 82d750239e554f0c73f8db3581761fffab0292c6

URL: https://github.com/llvm/llvm-project/commit/82d750239e554f0c73f8db3581761fffab0292c6
DIFF: https://github.com/llvm/llvm-project/commit/82d750239e554f0c73f8db3581761fffab0292c6.diff

LOG: llvm-reduce: Handle nneg flag

Added: 
    

Modified: 
    llvm/test/tools/llvm-reduce/reduce-flags.ll
    llvm/tools/llvm-reduce/deltas/ReduceInstructionFlags.cpp

Removed: 
    


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diff  --git a/llvm/test/tools/llvm-reduce/reduce-flags.ll b/llvm/test/tools/llvm-reduce/reduce-flags.ll
index 4745f98db46b1..429086effce80 100644
--- a/llvm/test/tools/llvm-reduce/reduce-flags.ll
+++ b/llvm/test/tools/llvm-reduce/reduce-flags.ll
@@ -200,3 +200,19 @@ define float @fadd_nnan_ninf_keep_nnan(float %a, float %b) {
   %op = fadd nnan ninf float %a, %b
   ret float %op
 }
+
+; CHECK-LABEL: @zext_nneg_drop(
+; INTERESTING: = zext
+; RESULT: zext i32
+define i64 @zext_nneg_drop(i32 %a) {
+  %op = zext nneg i32 %a to i64
+  ret i64 %op
+}
+
+; CHECK-LABEL: @zext_nneg_keep(
+; INTERESTING: = zext nneg
+; RESULT: zext nneg i32
+define i64 @zext_nneg_keep(i32 %a) {
+  %op = zext nneg i32 %a to i64
+  ret i64 %op
+}

diff  --git a/llvm/tools/llvm-reduce/deltas/ReduceInstructionFlags.cpp b/llvm/tools/llvm-reduce/deltas/ReduceInstructionFlags.cpp
index c73e74e4c25c9..96d3de01af7de 100644
--- a/llvm/tools/llvm-reduce/deltas/ReduceInstructionFlags.cpp
+++ b/llvm/tools/llvm-reduce/deltas/ReduceInstructionFlags.cpp
@@ -30,6 +30,9 @@ static void reduceFlagsInModule(Oracle &O, ReducerWorkItem &WorkItem) {
       } else if (auto *PE = dyn_cast<PossiblyExactOperator>(&I)) {
         if (PE->isExact() && !O.shouldKeep())
           I.setIsExact(false);
+      } else if (auto *NNI = dyn_cast<PossiblyNonNegInst>(&I)) {
+        if (NNI->hasNonNeg() && !O.shouldKeep())
+          NNI->setNonNeg(false);
       } else if (auto *GEP = dyn_cast<GetElementPtrInst>(&I)) {
         if (GEP->isInBounds() && !O.shouldKeep())
           GEP->setIsInBounds(false);