[ConstraintElim] Fix poison check before adding intrinsic facts

Author: el-ev

llvm/lib/Transforms/Scalar/ConstraintElimination.cpp

@@ -1137,12 +1137,12 @@ void State::addInfoFor(BasicBlock &BB) {
           FactOrCheck::getCheck(DT.getNode(&BB), cast<CallInst>(&I)));
       // TODO: Check if it is possible to instead only added the min/max facts
       // when simplifying uses of the min/max intrinsics.
-      if (!isGuaranteedNotToBePoison(&I))
-        break;
       [[fallthrough]];
     case Intrinsic::abs:
     case Intrinsic::uadd_sat:
     case Intrinsic::usub_sat:
+      if (!isGuaranteedNotToBePoison(&I))
+        break;
       WorkList.push_back(FactOrCheck::getInstFact(DT.getNode(&BB), &I));
       break;
     }

llvm/test/Transforms/ConstraintElimination/abs.ll

@@ -5,7 +5,8 @@ define i1 @abs_int_min_is_not_poison(i32 %arg) {
 ; CHECK-LABEL: define i1 @abs_int_min_is_not_poison(
 ; CHECK-SAME: i32 [[ARG:%.*]]) {
 ; CHECK-NEXT:    [[ABS:%.*]] = tail call i32 @llvm.abs.i32(i32 [[ARG]], i1 false)
-; CHECK-NEXT:    ret i1 true
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i32 [[ABS]], [[ARG]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %abs = tail call i32 @llvm.abs.i32(i32 %arg, i1 false)
   %cmp = icmp sge i32 %abs, %arg
@@ -16,7 +17,8 @@ define i1 @abs_int_min_is_poison(i32 %arg) {
 ; CHECK-LABEL: define i1 @abs_int_min_is_poison(
 ; CHECK-SAME: i32 [[ARG:%.*]]) {
 ; CHECK-NEXT:    [[ABS:%.*]] = tail call i32 @llvm.abs.i32(i32 [[ARG]], i1 true)
-; CHECK-NEXT:    ret i1 true
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i32 [[ABS]], [[ARG]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %abs = tail call i32 @llvm.abs.i32(i32 %arg, i1 true)
   %cmp = icmp sge i32 %abs, %arg
@@ -28,7 +30,8 @@ define i1 @abs_plus_one(i32 %arg) {
 ; CHECK-SAME: i32 [[ARG:%.*]]) {
 ; CHECK-NEXT:    [[ABS:%.*]] = tail call i32 @llvm.abs.i32(i32 [[ARG]], i1 true)
 ; CHECK-NEXT:    [[ABS_PLUS_ONE:%.*]] = add nsw i32 [[ABS]], 1
-; CHECK-NEXT:    ret i1 true
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i32 [[ABS_PLUS_ONE]], [[ARG]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %abs = tail call i32 @llvm.abs.i32(i32 %arg, i1 true)
   %abs_plus_one = add nsw i32 %abs, 1
@@ -41,7 +44,8 @@ define i1 @arg_minus_one_strict_less(i32 %arg) {
 ; CHECK-SAME: i32 [[ARG:%.*]]) {
 ; CHECK-NEXT:    [[ABS:%.*]] = tail call i32 @llvm.abs.i32(i32 [[ARG]], i1 true)
 ; CHECK-NEXT:    [[ARG_MINUS_ONE:%.*]] = add nsw i32 [[ARG]], -1
-; CHECK-NEXT:    ret i1 true
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[ARG_MINUS_ONE]], [[ABS]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %abs = tail call i32 @llvm.abs.i32(i32 %arg, i1 true)
   %arg_minus_one = add nsw i32 %arg, -1
@@ -54,7 +58,8 @@ define i1 @arg_minus_one_strict_greater(i32 %arg) {
 ; CHECK-SAME: i32 [[ARG:%.*]]) {
 ; CHECK-NEXT:    [[ABS:%.*]] = tail call i32 @llvm.abs.i32(i32 [[ARG]], i1 true)
 ; CHECK-NEXT:    [[ARG_MINUS_ONE:%.*]] = add nsw i32 [[ARG]], -1
-; CHECK-NEXT:    ret i1 false
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[ARG_MINUS_ONE]], [[ABS]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %abs = tail call i32 @llvm.abs.i32(i32 %arg, i1 true)
   %arg_minus_one = add nsw i32 %arg, -1
@@ -69,7 +74,8 @@ define i1 @abs_plus_one_unsigned_greater_or_equal_nonnegative_arg(i32 %arg) {
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP_ARG_NONNEGATIVE]])
 ; CHECK-NEXT:    [[ABS:%.*]] = tail call i32 @llvm.abs.i32(i32 [[ARG]], i1 true)
 ; CHECK-NEXT:    [[ABS_PLUS_ONE:%.*]] = add nuw i32 [[ABS]], 1
-; CHECK-NEXT:    ret i1 true
+; CHECK-NEXT:    [[CMP:%.*]] = icmp uge i32 [[ABS_PLUS_ONE]], [[ARG]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %cmp_arg_nonnegative = icmp sge i32 %arg, 0
   call void @llvm.assume(i1 %cmp_arg_nonnegative)
@@ -142,7 +148,8 @@ define i1 @abs_is_nonnegative_int_min_is_poison(i32 %arg) {
 ; CHECK-LABEL: define i1 @abs_is_nonnegative_int_min_is_poison(
 ; CHECK-SAME: i32 [[ARG:%.*]]) {
 ; CHECK-NEXT:    [[ABS:%.*]] = tail call i32 @llvm.abs.i32(i32 [[ARG]], i1 true)
-; CHECK-NEXT:    ret i1 true
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i32 [[ABS]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %abs = tail call i32 @llvm.abs.i32(i32 %arg, i1 true)
   %cmp = icmp sge i32 %abs, 0
@@ -152,7 +159,8 @@ define i1 @abs_is_nonnegative_int_min_is_poison(i32 %arg) {
 define i1 @abs_is_nonnegative_constant_arg() {
 ; CHECK-LABEL: define i1 @abs_is_nonnegative_constant_arg() {
 ; CHECK-NEXT:    [[ABS:%.*]] = tail call i32 @llvm.abs.i32(i32 -3, i1 true)
-; CHECK-NEXT:    ret i1 true
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i32 [[ABS]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %abs = tail call i32 @llvm.abs.i32(i32 -3, i1 true)
   %cmp = icmp sge i32 %abs, 0

llvm/test/Transforms/ConstraintElimination/uadd-usub-sat.ll

@@ -8,7 +8,9 @@ define i1 @uadd_sat_uge(i64 %a, i64 %b) {
 ; CHECK-LABEL: define i1 @uadd_sat_uge(
 ; CHECK-SAME: i64 [[A:%.*]], i64 [[B:%.*]]) {
 ; CHECK-NEXT:    [[ADD_SAT:%.*]] = call i64 @llvm.uadd.sat.i64(i64 [[A]], i64 [[B]])
-; CHECK-NEXT:    [[CMP:%.*]] = and i1 true, true
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp uge i64 [[ADD_SAT]], [[A]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp uge i64 [[ADD_SAT]], [[B]]
+; CHECK-NEXT:    [[CMP:%.*]] = and i1 [[CMP1]], [[CMP2]]
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %add.sat = call i64 @llvm.uadd.sat.i64(i64 %a, i64 %b)
@@ -22,7 +24,8 @@ define i1 @usub_sat_ule_lhs(i64 %a, i64 %b) {
 ; CHECK-LABEL: define i1 @usub_sat_ule_lhs(
 ; CHECK-SAME: i64 [[A:%.*]], i64 [[B:%.*]]) {
 ; CHECK-NEXT:    [[SUB_SAT:%.*]] = call i64 @llvm.usub.sat.i64(i64 [[A]], i64 [[B]])
-; CHECK-NEXT:    ret i1 true
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ule i64 [[SUB_SAT]], [[A]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %sub.sat = call i64 @llvm.usub.sat.i64(i64 %a, i64 %b)
   %cmp = icmp ule i64 %sub.sat, %a