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[InstCombine] Fold umax/umin(nuw_shl(z, x), nuw_shl(z, y)) -> nuw_shl(z, umax/umin(x, y)) and umax/umin(nuw_shl(x, z), nuw_shl(y, z)) -> nuw_shl(umax/umin(x, y), z) #131076

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Merged
dtcxzyw merged 15 commits into from
Mar 15, 2025
Merged

[InstCombine] Fold umax/umin(nuw_shl(z, x), nuw_shl(z, y)) -> nuw_shl(z, umax/umin(x, y)) and umax/umin(nuw_shl(x, z), nuw_shl(y, z)) -> nuw_shl(umax/umin(x, y), z) #131076

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3ea75f4
[InstCombine] Add pre-commit tests
el-ev Mar 13, 2025
a11d23d
[InstCombine] Fold ` umax(nuw_shl(C0, x), nuw_shl(C0, y)) -> nuw_shl(…
el-ev Mar 13, 2025
ed5a722
adjust test for variables as base
el-ev Mar 13, 2025
e09c615
adjust transformation for variables as base
el-ev Mar 13, 2025
ff81d9b
update affected testcase
el-ev Mar 13, 2025
77d3461
add nsw flag testcase
el-ev Mar 13, 2025
27e0a48
preserve nsw flag
el-ev Mar 13, 2025
2930936
add test for cases where rhs of shl are equal
el-ev Mar 13, 2025
fe32b6f
support cases where rhs are equal
el-ev Mar 13, 2025
080fc1d
refactor into `foldIntrinsicUsingDistributiveLaws`
el-ev Mar 14, 2025
3133f1d
update tests
el-ev Mar 14, 2025
46f31fc
codestyle
el-ev Mar 14, 2025
6cbc76d
fix intrinsic-distributive.ll commutative tests
el-ev Mar 14, 2025
e313f96
add intrinsic-distributive commutative regression tests
el-ev Mar 14, 2025
7fda0f4
fix missed swap pattern
el-ev Mar 14, 2025
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13 changes: 13 additions & 0 deletions llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1887,6 +1887,19 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
if (Instruction *I = foldMaxMulShift(I1, I0))
return I;
}

// umax(nuw_shl(C0, x), nuw_shl(C0, y)) -> nuw_shl(C0, umax(x, y))
// umin(nuw_shl(C0, x), nuw_shl(C0, y)) -> nuw_shl(C0, umin(x, y))
const APInt *C1, *C2;
if (match(I0, m_OneUse(m_NUWShl(m_APInt(C1), m_Value()))) &&
match(I1, m_OneUse(m_NUWShl(m_APInt(C2), m_Value()))) && *C1 == *C2) {
Value *X = cast<ShlOperator>(I0)->getOperand(1);
Value *Y = cast<ShlOperator>(I1)->getOperand(1);
Value *MaxMin = Builder.CreateBinaryIntrinsic(IID, X, Y);
return BinaryOperator::CreateNUWShl(ConstantInt::get(I0->getType(), *C1),
MaxMin);
}

// If both operands of unsigned min/max are sign-extended, it is still ok
// to narrow the operation.
[[fallthrough]];
Expand Down
232 changes: 232 additions & 0 deletions llvm/test/Transforms/InstCombine/shift-uminmax.ll
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@@ -0,0 +1,232 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

; For the following patterns:
; umax(nuw_shl(C0, x), nuw_shl(C0, y)) -> nuw_shl(C0, umax(x, y))
; umin(nuw_shl(C0, x), nuw_shl(C0, y)) -> nuw_shl(C0, umin(x, y))

define i32 @test_umax_shl_const1(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umax_shl_const1(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.umax.i32(i32 [[X]], i32 [[Y]])
; CHECK-NEXT: [[MAX:%.*]] = shl nuw i32 1, [[TMP1]]
; CHECK-NEXT: ret i32 [[MAX]]
;
%shl_x = shl nuw i32 1, %x
%shl_y = shl nuw i32 1, %y
%max = call i32 @llvm.umax.i32(i32 %shl_x, i32 %shl_y)
ret i32 %max
}

define i32 @test_umin_shl_const1(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umin_shl_const1(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.umin.i32(i32 [[X]], i32 [[Y]])
; CHECK-NEXT: [[MIN:%.*]] = shl nuw i32 1, [[TMP1]]
; CHECK-NEXT: ret i32 [[MIN]]
;
%shl_x = shl nuw i32 1, %x
%shl_y = shl nuw i32 1, %y
%min = call i32 @llvm.umin.i32(i32 %shl_x, i32 %shl_y)
ret i32 %min
}

define i32 @test_umax_shl_const5(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umax_shl_const5(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.umax.i32(i32 [[X]], i32 [[Y]])
; CHECK-NEXT: [[MAX:%.*]] = shl nuw i32 5, [[TMP1]]
; CHECK-NEXT: ret i32 [[MAX]]
;
%shl_x = shl nuw i32 5, %x
%shl_y = shl nuw i32 5, %y
%max = call i32 @llvm.umax.i32(i32 %shl_x, i32 %shl_y)
ret i32 %max
}

define i32 @test_umin_shl_const5(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umin_shl_const5(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.umin.i32(i32 [[X]], i32 [[Y]])
; CHECK-NEXT: [[MIN:%.*]] = shl nuw i32 5, [[TMP1]]
; CHECK-NEXT: ret i32 [[MIN]]
;
%shl_x = shl nuw i32 5, %x
%shl_y = shl nuw i32 5, %y
%min = call i32 @llvm.umin.i32(i32 %shl_x, i32 %shl_y)
ret i32 %min
}

declare void @use(i8)

define i32 @test_umax_shl_const1_multi_use(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umax_shl_const1_multi_use(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[SHL_X:%.*]] = shl nuw i32 1, [[X]]
; CHECK-NEXT: [[SHL_Y:%.*]] = shl nuw i32 1, [[Y]]
; CHECK-NEXT: call void @use(i32 [[SHL_X]])
; CHECK-NEXT: call void @use(i32 [[SHL_Y]])
; CHECK-NEXT: [[MAX:%.*]] = call i32 @llvm.umax.i32(i32 [[SHL_X]], i32 [[SHL_Y]])
; CHECK-NEXT: ret i32 [[MAX]]
;
%shl_x = shl nuw i32 1, %x
%shl_y = shl nuw i32 1, %y
call void @use(i32 %shl_x)
call void @use(i32 %shl_y)
%max = call i32 @llvm.umax.i32(i32 %shl_x, i32 %shl_y)
ret i32 %max
}

define i32 @test_umin_shl_const1_multi_use(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umin_shl_const1_multi_use(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[SHL_X:%.*]] = shl nuw i32 1, [[X]]
; CHECK-NEXT: [[SHL_Y:%.*]] = shl nuw i32 1, [[Y]]
; CHECK-NEXT: call void @use(i32 [[SHL_X]])
; CHECK-NEXT: call void @use(i32 [[SHL_Y]])
; CHECK-NEXT: [[MIN:%.*]] = call i32 @llvm.umin.i32(i32 [[SHL_X]], i32 [[SHL_Y]])
; CHECK-NEXT: ret i32 [[MIN]]
;
%shl_x = shl nuw i32 1, %x
%shl_y = shl nuw i32 1, %y
call void @use(i32 %shl_x)
call void @use(i32 %shl_y)
%min = call i32 @llvm.umin.i32(i32 %shl_x, i32 %shl_y)
ret i32 %min
}

define i32 @test_umax_shl_const1_commuted(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umax_shl_const1_commuted(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.umax.i32(i32 [[Y]], i32 [[X]])
; CHECK-NEXT: [[MAX:%.*]] = shl nuw i32 1, [[TMP1]]
; CHECK-NEXT: ret i32 [[MAX]]
;
%shl_x = shl nuw i32 1, %x
%shl_y = shl nuw i32 1, %y
%max = call i32 @llvm.umax.i32(i32 %shl_y, i32 %shl_x)
ret i32 %max
}

define i32 @test_umin_shl_const1_commuted(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umin_shl_const1_commuted(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.umin.i32(i32 [[Y]], i32 [[X]])
; CHECK-NEXT: [[MIN:%.*]] = shl nuw i32 1, [[TMP1]]
; CHECK-NEXT: ret i32 [[MIN]]
;
%shl_x = shl nuw i32 1, %x
%shl_y = shl nuw i32 1, %y
%min = call i32 @llvm.umin.i32(i32 %shl_y, i32 %shl_x)
ret i32 %min
}

define <2 x i32> @test_umax_shl_vector_splat(<2 x i32> %x, <2 x i32> %y) {
; CHECK-LABEL: define <2 x i32> @test_umax_shl_vector_splat(
; CHECK-SAME: <2 x i32> [[X:%.*]], <2 x i32> [[Y:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = call <2 x i32> @llvm.umax.v2i32(<2 x i32> [[X]], <2 x i32> [[Y]])
; CHECK-NEXT: [[MAX:%.*]] = shl nuw <2 x i32> splat (i32 1), [[TMP1]]
; CHECK-NEXT: ret <2 x i32> [[MAX]]
;
%shl_x = shl nuw <2 x i32> <i32 1, i32 1>, %x
%shl_y = shl nuw <2 x i32> <i32 1, i32 1>, %y
%max = call <2 x i32> @llvm.umax.v2i32(<2 x i32> %shl_x, <2 x i32> %shl_y)
ret <2 x i32> %max
}

define <2 x i32> @test_umin_shl_vector_splat(<2 x i32> %x, <2 x i32> %y) {
; CHECK-LABEL: define <2 x i32> @test_umin_shl_vector_splat(
; CHECK-SAME: <2 x i32> [[X:%.*]], <2 x i32> [[Y:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[X]], <2 x i32> [[Y]])
; CHECK-NEXT: [[MIN:%.*]] = shl nuw <2 x i32> splat (i32 1), [[TMP1]]
; CHECK-NEXT: ret <2 x i32> [[MIN]]
;
%shl_x = shl nuw <2 x i32> <i32 1, i32 1>, %x
%shl_y = shl nuw <2 x i32> <i32 1, i32 1>, %y
%min = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %shl_x, <2 x i32> %shl_y)
ret <2 x i32> %min
}

define <2 x i32> @test_umax_shl_vector_non_splat(<2 x i32> %x, <2 x i32> %y) {
; CHECK-LABEL: define <2 x i32> @test_umax_shl_vector_non_splat(
; CHECK-SAME: <2 x i32> [[X:%.*]], <2 x i32> [[Y:%.*]]) {
; CHECK-NEXT: [[SHL_X:%.*]] = shl nuw <2 x i32> <i32 1, i32 2>, [[X]]
; CHECK-NEXT: [[SHL_Y:%.*]] = shl nuw <2 x i32> <i32 1, i32 2>, [[Y]]
; CHECK-NEXT: [[MAX:%.*]] = call <2 x i32> @llvm.umax.v2i32(<2 x i32> [[SHL_X]], <2 x i32> [[SHL_Y]])
; CHECK-NEXT: ret <2 x i32> [[MAX]]
;
%shl_x = shl nuw <2 x i32> <i32 1, i32 2>, %x
%shl_y = shl nuw <2 x i32> <i32 1, i32 2>, %y
%max = call <2 x i32> @llvm.umax.v2i32(<2 x i32> %shl_x, <2 x i32> %shl_y)
ret <2 x i32> %max
}

define <2 x i32> @test_umin_shl_vector_non_splat(<2 x i32> %x, <2 x i32> %y) {
; CHECK-LABEL: define <2 x i32> @test_umin_shl_vector_non_splat(
; CHECK-SAME: <2 x i32> [[X:%.*]], <2 x i32> [[Y:%.*]]) {
; CHECK-NEXT: [[SHL_X:%.*]] = shl nuw <2 x i32> <i32 1, i32 2>, [[X]]
; CHECK-NEXT: [[SHL_Y:%.*]] = shl nuw <2 x i32> <i32 1, i32 2>, [[Y]]
; CHECK-NEXT: [[MIN:%.*]] = call <2 x i32> @llvm.umin.v2i32(<2 x i32> [[SHL_X]], <2 x i32> [[SHL_Y]])
; CHECK-NEXT: ret <2 x i32> [[MIN]]
;
%shl_x = shl nuw <2 x i32> <i32 1, i32 2>, %x
%shl_y = shl nuw <2 x i32> <i32 1, i32 2>, %y
%min = call <2 x i32> @llvm.umin.v2i32(<2 x i32> %shl_x, <2 x i32> %shl_y)
ret <2 x i32> %min
}

define i32 @test_umax_shl_different_base(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umax_shl_different_base(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[SHL_X:%.*]] = shl nuw i32 1, [[X]]
; CHECK-NEXT: [[SHL_Y:%.*]] = shl nuw i32 2, [[Y]]
; CHECK-NEXT: [[MAX:%.*]] = call i32 @llvm.umax.i32(i32 [[SHL_X]], i32 [[SHL_Y]])
; CHECK-NEXT: ret i32 [[MAX]]
;
%shl_x = shl nuw i32 1, %x
%shl_y = shl nuw i32 2, %y
%max = call i32 @llvm.umax.i32(i32 %shl_x, i32 %shl_y)
ret i32 %max
}

define i32 @test_umin_shl_different_base(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umin_shl_different_base(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[SHL_X:%.*]] = shl nuw i32 1, [[X]]
; CHECK-NEXT: [[SHL_Y:%.*]] = shl nuw i32 2, [[Y]]
; CHECK-NEXT: [[MIN:%.*]] = call i32 @llvm.umin.i32(i32 [[SHL_X]], i32 [[SHL_Y]])
; CHECK-NEXT: ret i32 [[MIN]]
;
%shl_x = shl nuw i32 1, %x
%shl_y = shl nuw i32 2, %y
%min = call i32 @llvm.umin.i32(i32 %shl_x, i32 %shl_y)
ret i32 %min
}

define i32 @test_umax_shl_no_nuw_flag(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umax_shl_no_nuw_flag(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[SHL_X:%.*]] = shl i32 2, [[X]]
; CHECK-NEXT: [[SHL_Y:%.*]] = shl i32 2, [[Y]]
; CHECK-NEXT: [[MAX:%.*]] = call i32 @llvm.umax.i32(i32 [[SHL_X]], i32 [[SHL_Y]])
; CHECK-NEXT: ret i32 [[MAX]]
;
%shl_x = shl i32 2, %x
%shl_y = shl i32 2, %y
%max = call i32 @llvm.umax.i32(i32 %shl_x, i32 %shl_y)
ret i32 %max
}

define i32 @test_umin_shl_no_nuw_flag(i32 %x, i32 %y) {
; CHECK-LABEL: define i32 @test_umin_shl_no_nuw_flag(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[SHL_X:%.*]] = shl i32 2, [[X]]
; CHECK-NEXT: [[SHL_Y:%.*]] = shl i32 2, [[Y]]
; CHECK-NEXT: [[MIN:%.*]] = call i32 @llvm.umin.i32(i32 [[SHL_X]], i32 [[SHL_Y]])
; CHECK-NEXT: ret i32 [[MIN]]
;
%shl_x = shl i32 2, %x
%shl_y = shl i32 2, %y
%min = call i32 @llvm.umin.i32(i32 %shl_x, i32 %shl_y)
ret i32 %min
}
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