[ValueTracking] Handle non-canonical operand order in isImpliedCondICmps

We don't always have canonical order here, so do it manually.

Author: goldsteinn

llvm/lib/Analysis/ValueTracking.cpp

@@ -8532,6 +8532,16 @@ static std::optional<bool> isImpliedCondICmps(const ICmpInst *LHS,
   CmpInst::Predicate LPred =
       LHSIsTrue ? LHS->getPredicate() : LHS->getInversePredicate();
 
+  // We can have non-canonical operands, so try to normalize any common operand
+  // to L0/R0.
+  if (L0 == R1) {
+    std::swap(R0, R1);
+    RPred = ICmpInst::getSwappedPredicate(RPred);
+  }
+  if (R0 == L1) {
+    std::swap(L0, L1);
+    LPred = ICmpInst::getSwappedPredicate(LPred);
+  }
   // Can we infer anything when the 0-operands match and the 1-operands are
   // constants (not necessarily matching)?
   const APInt *LC, *RC;

llvm/test/Transforms/InstCombine/assume.ll

@@ -386,7 +386,7 @@ define i1 @nonnull5(ptr %a) {
 define i32 @assumption_conflicts_with_known_bits(i32 %a, i32 %b) {
 ; CHECK-LABEL: @assumption_conflicts_with_known_bits(
 ; CHECK-NEXT:    store i1 true, ptr poison, align 1
-; CHECK-NEXT:    ret i32 1
+; CHECK-NEXT:    ret i32 poison
 ;
   %and1 = and i32 %b, 3
   %B1 = lshr i32 %and1, %and1

llvm/test/Transforms/InstCombine/icmp-select-implies-common-op.ll

@@ -3,10 +3,10 @@
 
 define i1 @sgt_3_impliesF_eq_2(i8 %x, i8 %y) {
 ; CHECK-LABEL: @sgt_3_impliesF_eq_2(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[X:%.*]], 3
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP]], i8 2, i8 [[Y:%.*]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp eq i8 [[SEL]], [[X]]
-; CHECK-NEXT:    ret i1 [[CMP2]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[X:%.*]], 4
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp eq i8 [[SEL:%.*]], [[X]]
+; CHECK-NEXT:    [[CMP3:%.*]] = select i1 [[CMP]], i1 [[CMP2]], i1 false
+; CHECK-NEXT:    ret i1 [[CMP3]]
 ;
   %cmp = icmp sgt i8 %x, 3
   %sel = select i1 %cmp, i8 2, i8 %y
@@ -16,10 +16,10 @@ define i1 @sgt_3_impliesF_eq_2(i8 %x, i8 %y) {
 
 define i1 @sgt_3_impliesT_sgt_2(i8 %x, i8 %y) {
 ; CHECK-LABEL: @sgt_3_impliesT_sgt_2(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[X:%.*]], 3
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP]], i8 2, i8 [[Y:%.*]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt i8 [[SEL]], [[X]]
-; CHECK-NEXT:    ret i1 [[CMP2]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[X:%.*]], 4
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt i8 [[SEL:%.*]], [[X]]
+; CHECK-NEXT:    [[CMP3:%.*]] = select i1 [[CMP]], i1 [[CMP2]], i1 false
+; CHECK-NEXT:    ret i1 [[CMP3]]
 ;
   %cmp = icmp sgt i8 %x, 3
   %sel = select i1 %cmp, i8 2, i8 %y
@@ -68,10 +68,10 @@ define i1 @ult_x_impliesT_eq_umax_todo(i8 %x, i8 %y, i8 %z) {
 
 define i1 @ult_1_impliesF_eq_1(i8 %x, i8 %y) {
 ; CHECK-LABEL: @ult_1_impliesF_eq_1(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[SEL:%.*]], 0
-; CHECK-NEXT:    [[X:%.*]] = select i1 [[CMP]], i8 1, i8 [[Y:%.*]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp eq i8 [[X]], [[SEL]]
-; CHECK-NEXT:    ret i1 [[CMP2]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[SEL:%.*]], 0
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp eq i8 [[X:%.*]], [[SEL]]
+; CHECK-NEXT:    [[CMP3:%.*]] = select i1 [[CMP]], i1 [[CMP2]], i1 false
+; CHECK-NEXT:    ret i1 [[CMP3]]
 ;
   %cmp = icmp ult i8 %x, 1
   %sel = select i1 %cmp, i8 1, i8 %y

llvm/test/Transforms/InstCombine/select.ll

@@ -2925,10 +2925,8 @@ define i8 @select_replacement_loop3(i32 noundef %x) {
 
 define i16 @select_replacement_loop4(i16 noundef %p_12) {
 ; CHECK-LABEL: @select_replacement_loop4(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i16 [[P_12:%.*]], 2
-; CHECK-NEXT:    [[AND1:%.*]] = and i16 [[P_12]], 1
-; CHECK-NEXT:    [[AND2:%.*]] = select i1 [[CMP1]], i16 [[AND1]], i16 0
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp eq i16 [[AND2]], [[P_12]]
+; CHECK-NEXT:    [[AND1:%.*]] = and i16 [[P_12:%.*]], 1
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i16 [[P_12]], 2
 ; CHECK-NEXT:    [[AND3:%.*]] = select i1 [[CMP2]], i16 [[AND1]], i16 0
 ; CHECK-NEXT:    ret i16 [[AND3]]
 ;

llvm/test/Transforms/InstCombine/shift.ll

@@ -1751,12 +1751,11 @@ define void @ashr_out_of_range_1(ptr %A) {
 ; CHECK-NEXT:    [[L:%.*]] = load i177, ptr [[A:%.*]], align 4
 ; CHECK-NEXT:    [[L_FROZEN:%.*]] = freeze i177 [[L]]
 ; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i177 [[L_FROZEN]], -1
-; CHECK-NEXT:    [[B:%.*]] = select i1 [[TMP1]], i177 0, i177 [[L_FROZEN]]
-; CHECK-NEXT:    [[TMP2:%.*]] = trunc i177 [[B]] to i64
+; CHECK-NEXT:    [[TMP6:%.*]] = trunc i177 [[L_FROZEN]] to i64
+; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP1]], i64 0, i64 [[TMP6]]
 ; CHECK-NEXT:    [[TMP3:%.*]] = getelementptr i177, ptr [[A]], i64 [[TMP2]]
 ; CHECK-NEXT:    [[G11:%.*]] = getelementptr i8, ptr [[TMP3]], i64 -24
-; CHECK-NEXT:    [[C17:%.*]] = icmp sgt i177 [[B]], [[L_FROZEN]]
-; CHECK-NEXT:    [[TMP4:%.*]] = sext i1 [[C17]] to i64
+; CHECK-NEXT:    [[TMP4:%.*]] = sext i1 [[TMP1]] to i64
 ; CHECK-NEXT:    [[G62:%.*]] = getelementptr i177, ptr [[G11]], i64 [[TMP4]]
 ; CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i177 [[L_FROZEN]], -1
 ; CHECK-NEXT:    [[B28:%.*]] = select i1 [[TMP5]], i177 0, i177 [[L_FROZEN]]