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[InstCombine] Improve coverage of foldSelectValueEquivalence for non-constants #94719

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[InstCombine] Improve coverage of foldSelectValueEquivalence for non-constants #94719

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9895c99
[InstCombine] Add tests for expanding `foldSelectValueEquivalence`; NFC
goldsteinn Apr 10, 2024
ed53a45
[InstCombine] Improve coverage of `foldSelectValueEquivalence` for no…
goldsteinn Jun 22, 2024
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2 changes: 1 addition & 1 deletion llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1310,7 +1310,7 @@ Instruction *InstCombinerImpl::foldSelectValueEquivalence(SelectInst &Sel,

// If NewOp is a constant and OldOp is not replace iff NewOp doesn't
// contain and undef elements.
if (match(NewOp, m_ImmConstant())) {
if (match(NewOp, m_ImmConstant()) || NewOp == V) {
if (isGuaranteedNotToBeUndef(NewOp, SQ.AC, &Sel, &DT))
return replaceOperand(Sel, Swapped ? 2 : 1, V);
return nullptr;
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184 changes: 184 additions & 0 deletions llvm/test/Transforms/InstCombine/select-cmp-eq-op-fold.ll
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Original file line number Diff line number Diff line change
@@ -0,0 +1,184 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

declare void @use.i1(i1)
declare void @use.i8(i8)
define i8 @replace_with_y_noundef(i8 %x, i8 noundef %y, i8 %z) {
; CHECK-LABEL: @replace_with_y_noundef(
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[Z:%.*]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%cmp = icmp eq i8 %x, %y
%and = and i8 %x, %y
%sel = select i1 %cmp, i8 %and, i8 %z
ret i8 %sel
}

define i8 @replace_with_x_noundef(i8 noundef %x, i8 %y, i8 %z) {
; CHECK-LABEL: @replace_with_x_noundef(
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: call void @use.i1(i1 [[CMP]])
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[Z:%.*]], i8 [[X]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%cmp = icmp ne i8 %x, %y
call void @use.i1(i1 %cmp)
%and = or i8 %x, %y
%sel = select i1 %cmp, i8 %z, i8 %and
ret i8 %sel
}

define i8 @replace_with_x_maybe_undef_fail(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @replace_with_x_maybe_undef_fail(
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: call void @use.i1(i1 [[CMP]])
; CHECK-NEXT: [[AND:%.*]] = or i8 [[X]], [[Y]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[Z:%.*]], i8 [[AND]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%cmp = icmp ne i8 %x, %y
call void @use.i1(i1 %cmp)
%and = or i8 %x, %y
%sel = select i1 %cmp, i8 %z, i8 %and
ret i8 %sel
}

define i8 @replace_with_y_for_new_oneuse(i8 noundef %xx, i8 noundef %y, i8 %z) {
; CHECK-LABEL: @replace_with_y_for_new_oneuse(
; CHECK-NEXT: [[X:%.*]] = mul i8 [[XX:%.*]], 13
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X]], [[Y:%.*]]
; CHECK-NEXT: [[ADD:%.*]] = add nuw i8 [[X]], [[Y]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[ADD]], i8 [[Z:%.*]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%x = mul i8 %xx, 13
%cmp = icmp eq i8 %x, %y
%add = add nuw i8 %x, %y
%sel = select i1 %cmp, i8 %add, i8 %z
ret i8 %sel
}

define i8 @replace_with_y_for_new_oneuse2(i8 %xx, i8 noundef %y, i8 %z, i8 %q) {
; CHECK-LABEL: @replace_with_y_for_new_oneuse2(
; CHECK-NEXT: [[X:%.*]] = mul i8 [[XX:%.*]], 13
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X]], [[Y:%.*]]
; CHECK-NEXT: [[ADD:%.*]] = add nuw i8 [[X]], [[Q:%.*]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[ADD]], i8 [[Z:%.*]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%x = mul i8 %xx, 13
%cmp = icmp eq i8 %x, %y
%add = add nuw i8 %x, %q
%sel = select i1 %cmp, i8 %add, i8 %z
ret i8 %sel
}

define i8 @replace_with_x_for_new_oneuse(i8 noundef %xx, i8 noundef %yy, i8 %z, i8 %w) {
; CHECK-LABEL: @replace_with_x_for_new_oneuse(
; CHECK-NEXT: [[X:%.*]] = mul i8 [[XX:%.*]], 13
; CHECK-NEXT: [[Y:%.*]] = add i8 [[YY:%.*]], [[W:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X]], [[Y]]
; CHECK-NEXT: [[MUL:%.*]] = mul i8 [[X]], [[Y]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[MUL]], i8 [[Z:%.*]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%x = mul i8 %xx, 13
%y = add i8 %yy, %w
%cmp = icmp eq i8 %x, %y
%mul = mul i8 %x, %y
%sel = select i1 %cmp, i8 %mul, i8 %z
ret i8 %sel
}

define i8 @replace_with_x_for_new_oneuse2(i8 noundef %xx, i8 %yy, i8 %z, i8 %w, i8 %q) {
; CHECK-LABEL: @replace_with_x_for_new_oneuse2(
; CHECK-NEXT: [[X:%.*]] = mul i8 [[XX:%.*]], 13
; CHECK-NEXT: [[Y:%.*]] = add i8 [[YY:%.*]], [[W:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X]], [[Y]]
; CHECK-NEXT: [[MUL:%.*]] = mul i8 [[Y]], [[Q:%.*]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[MUL]], i8 [[Z:%.*]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%x = mul i8 %xx, 13
%y = add i8 %yy, %w
%cmp = icmp eq i8 %x, %y
%mul = mul i8 %q, %y
%sel = select i1 %cmp, i8 %mul, i8 %z
ret i8 %sel
}

define i8 @replace_with_x_for_simple_binop(i8 noundef %xx, i8 %yy, i8 %z, i8 %w) {
; CHECK-LABEL: @replace_with_x_for_simple_binop(
; CHECK-NEXT: [[X:%.*]] = mul i8 [[XX:%.*]], 13
; CHECK-NEXT: [[Y:%.*]] = add i8 [[YY:%.*]], [[W:%.*]]
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X]], [[Y]]
; CHECK-NEXT: [[MUL:%.*]] = mul i8 [[X]], [[Y]]
; CHECK-NEXT: call void @use.i8(i8 [[Y]])
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[MUL]], i8 [[Z:%.*]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%x = mul i8 %xx, 13
%y = add i8 %yy, %w
%cmp = icmp eq i8 %x, %y
%mul = mul i8 %x, %y
call void @use.i8(i8 %y)
%sel = select i1 %cmp, i8 %mul, i8 %z
ret i8 %sel
}

define i8 @replace_with_none_for_new_oneuse_fail_maybe_undef(i8 %xx, i8 %y, i8 %z) {
; CHECK-LABEL: @replace_with_none_for_new_oneuse_fail_maybe_undef(
; CHECK-NEXT: [[X:%.*]] = mul i8 [[XX:%.*]], 13
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X]], [[Y:%.*]]
; CHECK-NEXT: [[MUL:%.*]] = mul i8 [[X]], [[Y]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[MUL]], i8 [[Z:%.*]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%x = mul i8 %xx, 13
%cmp = icmp eq i8 %x, %y
%mul = mul i8 %x, %y
%sel = select i1 %cmp, i8 %mul, i8 %z
ret i8 %sel
}

define i8 @replace_with_y_for_simple_binop(i8 %x, i8 noundef %y, i8 %z) {
; CHECK-LABEL: @replace_with_y_for_simple_binop(
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[MUL:%.*]] = mul nsw i8 [[X]], [[Y]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[MUL]], i8 [[Z:%.*]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%cmp = icmp eq i8 %x, %y
%mul = mul nsw i8 %x, %y
%sel = select i1 %cmp, i8 %mul, i8 %z
ret i8 %sel
}

define i8 @replace_with_y_for_simple_binop_fail_multiuse(i8 %x, i8 noundef %y, i8 %z) {
; CHECK-LABEL: @replace_with_y_for_simple_binop_fail_multiuse(
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[MUL:%.*]] = mul nsw i8 [[X]], [[Y]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[MUL]], i8 [[Z:%.*]]
; CHECK-NEXT: call void @use.i8(i8 [[MUL]])
; CHECK-NEXT: ret i8 [[SEL]]
;
%cmp = icmp eq i8 %x, %y
%mul = mul nsw i8 %x, %y
%sel = select i1 %cmp, i8 %mul, i8 %z
call void @use.i8(i8 %mul)
ret i8 %sel
}

define i8 @replace_with_y_for_simple_binop_fail(i8 %x, i8 noundef %y, i8 %z, i8 %q) {
; CHECK-LABEL: @replace_with_y_for_simple_binop_fail(
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[MUL:%.*]] = mul nsw i8 [[X]], [[Q:%.*]]
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[CMP]], i8 [[MUL]], i8 [[Z:%.*]]
; CHECK-NEXT: ret i8 [[SEL]]
;
%cmp = icmp eq i8 %x, %y
%mul = mul nsw i8 %x, %q
%sel = select i1 %cmp, i8 %mul, i8 %z
ret i8 %sel
}
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