[LVI] Handle commuted SPF min/max operands

We need to check that the operands of the min/max are the operands of the select, but we don't care which order they are in.
llvm · Jan 18, 2022 · 9e68557 · 9e68557
1 parent d15823e
commit 9e68557
Show file tree

Hide file tree

Showing 2 changed files with 3 additions and 3 deletions.
diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -828,7 +828,8 @@ Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueSelect(
     // Is this a min specifically of our two inputs?  (Avoid the risk of
     // ValueTracking getting smarter looking back past our immediate inputs.)
     if (SelectPatternResult::isMinOrMax(SPR.Flavor) &&
-        LHS == SI->getTrueValue() && RHS == SI->getFalseValue()) {
+        ((LHS == SI->getTrueValue() && RHS == SI->getFalseValue()) ||
+         (RHS == SI->getTrueValue() && LHS == SI->getFalseValue()))) {
       ConstantRange ResultCR = [&]() {
         switch (SPR.Flavor) {
         default:

diff --git a/llvm/test/Transforms/CorrelatedValuePropagation/basic.ll b/llvm/test/Transforms/CorrelatedValuePropagation/basic.ll
@@ -665,8 +665,7 @@ define i1 @umin_rhs_overdefined_lhs_range(i32 %a, i32 %b) {
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[ASSUME]])
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp uge i32 [[A:%.*]], [[B]]
 ; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP]], i32 [[B]], i32 [[A]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i32 [[SEL]], 42
-; CHECK-NEXT:    ret i1 [[CMP2]]
+; CHECK-NEXT:    ret i1 true
 ;
   %assume = icmp ult i32 %b, 42
   call void @llvm.assume(i1 %assume)