if (Instruction *NI = foldSelectICmp(I.getSwappedPredicate(), SI, Op0, I))
return NI;
+ // In case of a comparison with two select instructions having the same
+ // condition, check whether one of the resulting branches can be simplified.
+ // If so, just compare the other branch and select the appropriate result.
+ // For example:
+ // %tmp1 = select i1 %cmp, i32 %y, i32 %x
+ // %tmp2 = select i1 %cmp, i32 %z, i32 %x
+ // %cmp2 = icmp slt i32 %tmp2, %tmp1
+ // The icmp will result false for the false value of selects and the result
+ // will depend upon the comparison of true values of selects if %cmp is
+ // true. Thus, transform this into:
+ // %cmp = icmp slt i32 %y, %z
+ // %sel = select i1 %cond, i1 %cmp, i1 false
+ // This handles similar cases to transform.
+ {
+ Value *Cond, *A, *B, *C, *D;
+ if (match(Op0, m_Select(m_Value(Cond), m_Value(A), m_Value(B))) &&
+ match(Op1, m_Select(m_Specific(Cond), m_Value(C), m_Value(D))) &&
+ (Op0->hasOneUse() || Op1->hasOneUse())) {
+ // Check whether comparison of TrueValues can be simplified
+ if (Value *Res = simplifyICmpInst(Pred, A, C, SQ)) {
+ Value *NewICMP = Builder.CreateICmp(Pred, B, D);
+ return SelectInst::Create(Cond, Res, NewICMP);
+ }
+ // Check whether comparison of FalseValues can be simplified
+ if (Value *Res = simplifyICmpInst(Pred, B, D, SQ)) {
+ Value *NewICMP = Builder.CreateICmp(Pred, A, C);
+ return SelectInst::Create(Cond, NewICMP, Res);
+ }
+ }
+ }
+
// Try to optimize equality comparisons against alloca-based pointers.
if (Op0->getType()->isPointerTy() && I.isEquality()) {
assert(Op1->getType()->isPointerTy() && "Comparing pointer with non-pointer?");
; CHECK-LABEL: define i1 @both_sides_fold_slt
; CHECK-SAME: (i32 [[PARAM:%.*]], i1 [[COND:%.*]]) {
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[COND1:%.*]] = select i1 [[COND]], i32 1, i32 [[PARAM]]
-; CHECK-NEXT: [[COND6:%.*]] = select i1 [[COND]], i32 9, i32 [[PARAM]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[COND6]], [[COND1]]
-; CHECK-NEXT: ret i1 [[CMP]]
+; CHECK-NEXT: ret i1 false
;
entry:
%cond1 = select i1 %cond, i32 1, i32 %param
; CHECK-LABEL: define i1 @both_sides_fold_eq
; CHECK-SAME: (i32 [[PARAM:%.*]], i1 [[COND:%.*]]) {
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[COND1:%.*]] = select i1 [[COND]], i32 1, i32 [[PARAM]]
-; CHECK-NEXT: [[COND6:%.*]] = select i1 [[COND]], i32 9, i32 [[PARAM]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[COND6]], [[COND1]]
-; CHECK-NEXT: ret i1 [[CMP]]
+; CHECK-NEXT: [[NOT_COND:%.*]] = xor i1 [[COND]], true
+; CHECK-NEXT: ret i1 [[NOT_COND]]
;
entry:
%cond1 = select i1 %cond, i32 1, i32 %param
; CHECK-LABEL: define i1 @one_side_fold_slt
; CHECK-SAME: (i32 [[VAL1:%.*]], i32 [[VAL2:%.*]], i32 [[PARAM:%.*]], i1 [[COND:%.*]]) {
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[COND1:%.*]] = select i1 [[COND]], i32 [[VAL1]], i32 [[PARAM]]
-; CHECK-NEXT: [[COND6:%.*]] = select i1 [[COND]], i32 [[VAL2]], i32 [[PARAM]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[COND6]], [[COND1]]
+; CHECK-NEXT: [[TMP0:%.*]] = icmp slt i32 [[VAL2]], [[VAL1]]
+; CHECK-NEXT: [[CMP:%.*]] = select i1 [[COND]], i1 [[TMP0]], i1 false
; CHECK-NEXT: ret i1 [[CMP]]
;
entry:
; CHECK-LABEL: define i1 @one_side_fold_sgt
; CHECK-SAME: (i32 [[VAL1:%.*]], i32 [[VAL2:%.*]], i32 [[PARAM:%.*]], i1 [[COND:%.*]]) {
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[COND1:%.*]] = select i1 [[COND]], i32 [[PARAM]], i32 [[VAL1]]
-; CHECK-NEXT: [[COND6:%.*]] = select i1 [[COND]], i32 [[PARAM]], i32 [[VAL2]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[COND6]], [[COND1]]
+; CHECK-NEXT: [[TMP0:%.*]] = icmp sgt i32 [[VAL2]], [[VAL1]]
+; CHECK-NEXT: [[NOT_COND:%.*]] = xor i1 [[COND]], true
+; CHECK-NEXT: [[CMP:%.*]] = select i1 [[NOT_COND]], i1 [[TMP0]], i1 false
; CHECK-NEXT: ret i1 [[CMP]]
;
entry:
; CHECK-LABEL: define i1 @one_side_fold_eq
; CHECK-SAME: (i32 [[VAL1:%.*]], i32 [[VAL2:%.*]], i32 [[PARAM:%.*]], i1 [[COND:%.*]]) {
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[COND1:%.*]] = select i1 [[COND]], i32 [[VAL1]], i32 [[PARAM]]
-; CHECK-NEXT: [[COND6:%.*]] = select i1 [[COND]], i32 [[VAL2]], i32 [[PARAM]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[COND6]], [[COND1]]
+; CHECK-NEXT: [[TMP0:%.*]] = icmp eq i32 [[VAL2]], [[VAL1]]
+; CHECK-NEXT: [[NOT_COND:%.*]] = xor i1 [[COND]], true
+; CHECK-NEXT: [[CMP:%.*]] = select i1 [[NOT_COND]], i1 true, i1 [[TMP0]]
; CHECK-NEXT: ret i1 [[CMP]]
;
entry:
; CHECK-SAME: (i32 [[VAL1:%.*]], i32 [[VAL2:%.*]], i32 [[PARAM:%.*]], i1 [[COND:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[COND1:%.*]] = select i1 [[COND]], i32 [[VAL1]], i32 [[PARAM]]
-; CHECK-NEXT: [[COND6:%.*]] = select i1 [[COND]], i32 [[VAL2]], i32 [[PARAM]]
; CHECK-NEXT: call void @use(i32 [[COND1]])
-; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[COND6]], [[COND1]]
+; CHECK-NEXT: [[TMP0:%.*]] = icmp slt i32 [[VAL2]], [[VAL1]]
+; CHECK-NEXT: [[CMP:%.*]] = select i1 [[COND]], i1 [[TMP0]], i1 false
; CHECK-NEXT: ret i1 [[CMP]]
;
entry:
; CHECK-LABEL: define <4 x i1> @fold_vector_ops
; CHECK-SAME: (<4 x i32> [[VAL1:%.*]], <4 x i32> [[VAL2:%.*]], <4 x i32> [[PARAM:%.*]], i1 [[COND:%.*]]) {
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[COND1:%.*]] = select i1 [[COND]], <4 x i32> [[VAL1]], <4 x i32> [[PARAM]]
-; CHECK-NEXT: [[COND6:%.*]] = select i1 [[COND]], <4 x i32> [[VAL2]], <4 x i32> [[PARAM]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq <4 x i32> [[COND6]], [[COND1]]
+; CHECK-NEXT: [[TMP0:%.*]] = icmp eq <4 x i32> [[VAL2]], [[VAL1]]
+; CHECK-NEXT: [[CMP:%.*]] = select i1 [[COND]], <4 x i1> [[TMP0]], <4 x i1> <i1 true, i1 true, i1 true, i1 true>
; CHECK-NEXT: ret <4 x i1> [[CMP]]
;
entry:
; CHECK-LABEL: define <8 x i1> @fold_vector_cond_ops
; CHECK-SAME: (<8 x i32> [[VAL1:%.*]], <8 x i32> [[VAL2:%.*]], <8 x i32> [[PARAM:%.*]], <8 x i1> [[COND:%.*]]) {
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[COND1:%.*]] = select <8 x i1> [[COND]], <8 x i32> [[VAL1]], <8 x i32> [[PARAM]]
-; CHECK-NEXT: [[COND6:%.*]] = select <8 x i1> [[COND]], <8 x i32> [[VAL2]], <8 x i32> [[PARAM]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <8 x i32> [[COND6]], [[COND1]]
+; CHECK-NEXT: [[TMP0:%.*]] = icmp sgt <8 x i32> [[VAL2]], [[VAL1]]
+; CHECK-NEXT: [[CMP:%.*]] = select <8 x i1> [[COND]], <8 x i1> [[TMP0]], <8 x i1> zeroinitializer
; CHECK-NEXT: ret <8 x i1> [[CMP]]
;
entry: