Skip to content

[InstCombine] Enable FoldOpIntoSelect and foldOpIntoPhi when the Op's other parameter is non-const #166102

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
Nov 5, 2025
Merged

[InstCombine] Enable FoldOpIntoSelect and foldOpIntoPhi when the Op's other parameter is non-const #166102

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
e9a5d95
Enable FoldOpIntoSelect when the Op's other parameter is non-const
spaits Nov 2, 2025
fa3c083
Add test cases coming from #163108
spaits Nov 4, 2025
911b97e
Add test cases coming from #137161
spaits Nov 4, 2025
306dd28
Port test from #138373
spaits Nov 4, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 3 additions & 3 deletions llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2261,11 +2261,11 @@ Instruction *InstCombinerImpl::foldBinopWithPhiOperands(BinaryOperator &BO) {
}

Instruction *InstCombinerImpl::foldBinOpIntoSelectOrPhi(BinaryOperator &I) {
if (!isa<Constant>(I.getOperand(1)))
return nullptr;
bool IsOtherParamConst = isa<Constant>(I.getOperand(1));

if (auto *Sel = dyn_cast<SelectInst>(I.getOperand(0))) {
if (Instruction *NewSel = FoldOpIntoSelect(I, Sel))
if (Instruction *NewSel =
FoldOpIntoSelect(I, Sel, false, !IsOtherParamConst))
return NewSel;
} else if (auto *PN = dyn_cast<PHINode>(I.getOperand(0))) {
if (Instruction *NewPhi = foldOpIntoPhi(I, PN))
Expand Down
5 changes: 2 additions & 3 deletions llvm/test/Transforms/InstCombine/binop-phi-operands.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -653,12 +653,11 @@ define i8 @mul_const_incoming0_speculatable(i1 %b, i8 %x, i8 %y) {
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 [[B:%.*]], label [[IF:%.*]], label [[THEN:%.*]]
; CHECK: if:
; CHECK-NEXT: [[TMP0:%.*]] = mul i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: br label [[THEN]]
; CHECK: then:
; CHECK-NEXT: [[P0:%.*]] = phi i8 [ 42, [[ENTRY:%.*]] ], [ [[X:%.*]], [[IF]] ]
; CHECK-NEXT: [[P1:%.*]] = phi i8 [ 17, [[ENTRY]] ], [ [[Y:%.*]], [[IF]] ]
; CHECK-NEXT: [[R:%.*]] = phi i8 [ -54, [[ENTRY:%.*]] ], [ [[TMP0]], [[IF]] ]
; CHECK-NEXT: call void @sideeffect()
; CHECK-NEXT: [[R:%.*]] = mul i8 [[P0]], [[P1]]
; CHECK-NEXT: ret i8 [[R]]
;
entry:
Expand Down
2 changes: 1 addition & 1 deletion llvm/test/Transforms/InstCombine/binop-select.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -335,7 +335,7 @@ define i32 @sub_sel_op1_use(i1 %b) {

define float @fadd_sel_op0(i1 %b, float %x) {
; CHECK-LABEL: @fadd_sel_op0(
; CHECK-NEXT: [[R:%.*]] = select nnan i1 [[B:%.*]], float 0xFFF0000000000000, float 0x7FF0000000000000
; CHECK-NEXT: [[R:%.*]] = select i1 [[B:%.*]], float 0xFFF0000000000000, float 0x7FF0000000000000
; CHECK-NEXT: ret float [[R]]
;
%s = select i1 %b, float 0xFFF0000000000000, float 0x7FF0000000000000
Expand Down
10 changes: 4 additions & 6 deletions llvm/test/Transforms/InstCombine/dont-distribute-phi.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
define zeroext i1 @foo(i32 %arg) {
; CHECK-LABEL: @foo(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP1:%.*]] = icmp ne i32 [[ARG:%.*]], 37
; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i32 [[ARG:%.*]], 37
; CHECK-NEXT: br i1 [[CMP1]], label [[BB_ELSE:%.*]], label [[BB_THEN:%.*]]
; CHECK: bb_then:
; CHECK-NEXT: call void @bar()
Expand All @@ -16,8 +16,7 @@ define zeroext i1 @foo(i32 %arg) {
; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 [[ARG]], 17
; CHECK-NEXT: br label [[BB_EXIT]]
; CHECK: bb_exit:
; CHECK-NEXT: [[PHI1:%.*]] = phi i1 [ [[CMP2]], [[BB_ELSE]] ], [ undef, [[BB_THEN]] ]
; CHECK-NEXT: [[AND1:%.*]] = and i1 [[PHI1]], [[CMP1]]
; CHECK-NEXT: [[AND1:%.*]] = phi i1 [ [[CMP2]], [[BB_THEN]] ], [ false, [[BB_ELSE]] ]
; CHECK-NEXT: ret i1 [[AND1]]
;

Expand All @@ -43,7 +42,7 @@ bb_exit:
define zeroext i1 @foo_logical(i32 %arg) {
; CHECK-LABEL: @foo_logical(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP1:%.*]] = icmp ne i32 [[ARG:%.*]], 37
; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i32 [[ARG:%.*]], 37
; CHECK-NEXT: br i1 [[CMP1]], label [[BB_ELSE:%.*]], label [[BB_THEN:%.*]]
; CHECK: bb_then:
; CHECK-NEXT: call void @bar()
Expand All @@ -52,8 +51,7 @@ define zeroext i1 @foo_logical(i32 %arg) {
; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 [[ARG]], 17
; CHECK-NEXT: br label [[BB_EXIT]]
; CHECK: bb_exit:
; CHECK-NEXT: [[PHI1:%.*]] = phi i1 [ [[CMP2]], [[BB_ELSE]] ], [ undef, [[BB_THEN]] ]
; CHECK-NEXT: [[AND1:%.*]] = and i1 [[PHI1]], [[CMP1]]
; CHECK-NEXT: [[AND1:%.*]] = phi i1 [ [[CMP2]], [[BB_THEN]] ], [ false, [[BB_ELSE]] ]
; CHECK-NEXT: ret i1 [[AND1]]
;

Expand Down
4 changes: 2 additions & 2 deletions llvm/test/Transforms/InstCombine/fmul.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1222,7 +1222,7 @@ define <2 x double> @negate_if_true_wrong_constant(<2 x double> %px, i1 %cond) {
; X *fast (C ? 1.0 : 0.0) -> C ? X : 0.0
define float @fmul_select(float %x, i1 %c) {
; CHECK-LABEL: @fmul_select(
; CHECK-NEXT: [[MUL:%.*]] = select fast i1 [[C:%.*]], float [[X:%.*]], float 0.000000e+00
; CHECK-NEXT: [[MUL:%.*]] = select i1 [[C:%.*]], float [[X:%.*]], float 0.000000e+00
; CHECK-NEXT: ret float [[MUL]]
;
%sel = select i1 %c, float 1.0, float 0.0
Expand All @@ -1233,7 +1233,7 @@ define float @fmul_select(float %x, i1 %c) {
; X *fast (C ? 1.0 : 0.0) -> C ? X : 0.0
define <2 x float> @fmul_select_vec(<2 x float> %x, i1 %c) {
; CHECK-LABEL: @fmul_select_vec(
; CHECK-NEXT: [[MUL:%.*]] = select fast i1 [[C:%.*]], <2 x float> [[X:%.*]], <2 x float> zeroinitializer
; CHECK-NEXT: [[MUL:%.*]] = select i1 [[C:%.*]], <2 x float> [[X:%.*]], <2 x float> zeroinitializer
; CHECK-NEXT: ret <2 x float> [[MUL]]
;
%sel = select i1 %c, <2 x float> <float 1.0, float 1.0>, <2 x float> zeroinitializer
Expand Down
4 changes: 2 additions & 2 deletions llvm/test/Transforms/InstCombine/free-inversion.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -563,10 +563,10 @@ define i1 @test_inv_free(i1 %c1, i1 %c2, i1 %c3, i1 %c4) {
; CHECK: b2:
; CHECK-NEXT: br label [[EXIT]]
; CHECK: b3:
; CHECK-NEXT: [[TMP0:%.*]] = and i1 [[C3:%.*]], [[C4:%.*]]
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: [[VAL_NOT:%.*]] = phi i1 [ false, [[B1]] ], [ true, [[B2]] ], [ [[C3:%.*]], [[B3]] ]
; CHECK-NEXT: [[COND_NOT:%.*]] = and i1 [[VAL_NOT]], [[C4:%.*]]
; CHECK-NEXT: [[COND_NOT:%.*]] = phi i1 [ false, [[B1]] ], [ [[C4]], [[B2]] ], [ [[TMP0]], [[B3]] ]
; CHECK-NEXT: br i1 [[COND_NOT]], label [[B5:%.*]], label [[B4:%.*]]
; CHECK: b4:
; CHECK-NEXT: ret i1 true
Expand Down
4 changes: 2 additions & 2 deletions llvm/test/Transforms/InstCombine/recurrence.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -24,9 +24,9 @@ loop: ; preds = %loop, %entry
define i64 @test_or2(i64 %a, i64 %b) {
; CHECK-LABEL: @test_or2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[IV_NEXT:%.*]] = or i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV_NEXT:%.*]] = or i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: tail call void @use(i64 [[IV_NEXT]])
; CHECK-NEXT: br label [[LOOP]]
;
Expand Down Expand Up @@ -104,9 +104,9 @@ loop: ; preds = %loop, %entry
define i64 @test_and2(i64 %a, i64 %b) {
; CHECK-LABEL: @test_and2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[IV_NEXT:%.*]] = and i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV_NEXT:%.*]] = and i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: tail call void @use(i64 [[IV_NEXT]])
; CHECK-NEXT: br label [[LOOP]]
;
Expand Down
3 changes: 1 addition & 2 deletions llvm/test/Transforms/InstCombine/sub-gep.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -858,8 +858,7 @@ define i1 @_gep_phi2(ptr %str1, i64 %val2) {
; CHECK: while.end.i:
; CHECK-NEXT: br label [[_Z3FOOPKC_EXIT]]
; CHECK: _Z3fooPKc.exit:
; CHECK-NEXT: [[RETVAL_0_I:%.*]] = phi i64 [ 1, [[WHILE_END_I]] ], [ 0, [[LOR_LHS_FALSE_I]] ], [ 0, [[ENTRY:%.*]] ]
; CHECK-NEXT: [[TMP2:%.*]] = or i64 [[RETVAL_0_I]], [[VAL2:%.*]]
; CHECK-NEXT: [[TMP2:%.*]] = phi i64 [ 1, [[WHILE_END_I]] ], [ [[VAL2:%.*]], [[LOR_LHS_FALSE_I]] ], [ [[VAL2]], [[ENTRY:%.*]] ]
; CHECK-NEXT: [[TOBOOL:%.*]] = icmp eq i64 [[TMP2]], 0
; CHECK-NEXT: ret i1 [[TOBOOL]]
;
Expand Down
Loading