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Differential D148180

[InstCombine] Add tests for deducing constants based on condition in select; NFC
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Authored by goldstein.w.n on Apr 12 2023, 4:03 PM.

Details

Reviewers
nikic
spatel
majnemer
Commits
rGdb0706b7ccce: [InstCombine] Add tests for deducing constants based on condition in select; NFC

Diff Detail

Event Timeline

goldstein.w.n created this revision.Apr 12 2023, 4:03 PM
Herald added a project: Restricted Project. · View Herald TranscriptApr 12 2023, 4:03 PM
goldstein.w.n requested review of this revision.Apr 12 2023, 4:03 PM
Herald added a project: Restricted Project. · View Herald TranscriptApr 12 2023, 4:03 PM
Herald added a subscriber: llvm-commits. · View Herald Transcript
goldstein.w.n added reviewers: nikic, spatel, majnemer.Apr 12 2023, 4:05 PM
Herald added a subscriber: StephenFan. · View Herald TranscriptApr 12 2023, 4:05 PM
goldstein.w.n added a child revision: D146349: [InstCombine] Make `FoldOpIntoSelect` handle non-constants and use condition to deduce constants..Apr 12 2023, 4:05 PM
goldstein.w.n added a parent revision: D147900: [ValueTracking] Use `select` condition to help determine if `select` is non-zero.
Harbormaster completed remote builds in B225203: Diff 512997.Apr 12 2023, 4:38 PM
nikic accepted this revision.Apr 13 2023, 12:30 AM

LGTM

llvm/test/Transforms/InstCombine/binop-select.ll
81

Maybe add one more (negative) test with the select ops swapped, so we know the constant in the call but not the one in the select.

This revision is now accepted and ready to land.Apr 13 2023, 12:30 AM
goldstein.w.n updated this revision to Diff 513646.Apr 14 2023, 9:53 AM

Add negative test

goldstein.w.n marked an inline comment as done.Apr 14 2023, 9:53 AM
Harbormaster completed remote builds in B225657: Diff 513646.Apr 14 2023, 11:05 AM
Closed by commit rGdb0706b7ccce: [InstCombine] Add tests for deducing constants based on condition in select; NFC (authored by goldstein.w.n). · Explain WhyApr 14 2023, 11:14 AM
This revision was automatically updated to reflect the committed changes.
goldstein.w.n added a commit: rGdb0706b7ccce: [InstCombine] Add tests for deducing constants based on condition in select; NFC.
goldstein.w.n removed a parent revision: D147900: [ValueTracking] Use `select` condition to help determine if `select` is non-zero.May 19 2023, 2:27 PM

Revision Contents

PathSize
llvm/
test/
Transforms/
InstCombine/
40 lines

Diff 513684

llvm/test/Transforms/InstCombine/binop-select.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s ; RUN: opt < %s -passes=instcombine -S | FileCheck %s
declare void @use(i32) declare void @use(i32)
declare void @use_f32(float) declare void @use_f32(float)
declare void @use_v2f16(<2 x half>) declare void @use_v2f16(<2 x half>)
declare void @use_v2i8(<2 x i8>) declare void @use_v2i8(<2 x i8>)
declare i32 @llvm.sadd.sat.i32(i32, i32)
define i32 @test1(i1 %c, i32 %x, i32 %y) { define i32 @test1(i1 %c, i32 %x, i32 %y) {
; CHECK-LABEL: @test1( ; CHECK-LABEL: @test1(
; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[X:%.*]] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[X:%.*]]
; CHECK-NEXT: [[COND:%.*]] = select i1 [[C:%.*]], i32 [[SUB]], i32 [[Y:%.*]] ; CHECK-NEXT: [[COND:%.*]] = select i1 [[C:%.*]], i32 [[SUB]], i32 [[Y:%.*]]
; CHECK-NEXT: [[ADD:%.*]] = add i32 [[COND]], [[X]] ; CHECK-NEXT: [[ADD:%.*]] = add i32 [[COND]], [[X]]
; CHECK-NEXT: ret i32 [[ADD]] ; CHECK-NEXT: ret i32 [[ADD]]
; ;
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; CHECK-NEXT: [[ADD:%.*]] = add i32 [[COND]], [[X]] ; CHECK-NEXT: [[ADD:%.*]] = add i32 [[COND]], [[X]]
; CHECK-NEXT: ret i32 [[ADD]] ; CHECK-NEXT: ret i32 [[ADD]]
; ;
%cond = select i1 %c, i32 %x, i32 0 %cond = select i1 %c, i32 %x, i32 0
%add = add i32 %cond, %x %add = add i32 %cond, %x
ret i32 %add ret i32 %add
} }
define i32 @test_sub_deduce_true(i32 %x, i32 %y) {
; CHECK-LABEL: @test_sub_deduce_true(
; CHECK-NEXT: [[C:%.*]] = icmp eq i32 [[X:%.*]], 9
; CHECK-NEXT: [[COND:%.*]] = select i1 [[C]], i32 6, i32 [[Y:%.*]]
; CHECK-NEXT: [[SUB:%.*]] = call i32 @llvm.sadd.sat.i32(i32 [[X]], i32 [[COND]])
; CHECK-NEXT: ret i32 [[SUB]]
;
%c = icmp eq i32 %x, 9
%cond = select i1 %c, i32 6, i32 %y
nikicUnsubmitted
Done
ReplyInline Actions

Maybe add one more (negative) test with the select ops swapped, so we know the constant in the call but not the one in the select.

nikic: Maybe add one more (negative) test with the select ops swapped, so we know the constant in the…
%sub = call i32 @llvm.sadd.sat.i32(i32 %x, i32 %cond)
ret i32 %sub
}
define i32 @test_sub_deduce_true_no_const_fold(i32 %x, i32 %y) {
; CHECK-LABEL: @test_sub_deduce_true_no_const_fold(
; CHECK-NEXT: [[C:%.*]] = icmp eq i32 [[X:%.*]], 9
; CHECK-NEXT: [[COND:%.*]] = select i1 [[C]], i32 [[Y:%.*]], i32 6
; CHECK-NEXT: [[SUB:%.*]] = call i32 @llvm.sadd.sat.i32(i32 [[X]], i32 [[COND]])
; CHECK-NEXT: ret i32 [[SUB]]
;
%c = icmp eq i32 %x, 9
%cond = select i1 %c, i32 %y, i32 6
%sub = call i32 @llvm.sadd.sat.i32(i32 %x, i32 %cond)
ret i32 %sub
}
define i32 @test_sub_deduce_false(i32 %x, i32 %y) {
; CHECK-LABEL: @test_sub_deduce_false(
; CHECK-NEXT: [[C_NOT:%.*]] = icmp eq i32 [[X:%.*]], 9
; CHECK-NEXT: [[COND:%.*]] = select i1 [[C_NOT]], i32 7, i32 [[Y:%.*]]
; CHECK-NEXT: [[SUB:%.*]] = call i32 @llvm.sadd.sat.i32(i32 [[X]], i32 [[COND]])
; CHECK-NEXT: ret i32 [[SUB]]
;
%c = icmp ne i32 %x, 9
%cond = select i1 %c, i32 %y, i32 7
%sub = call i32 @llvm.sadd.sat.i32(i32 %x, i32 %cond)
ret i32 %sub
}
define i32 @test6(i1 %c, i32 %x, i32 %y) { define i32 @test6(i1 %c, i32 %x, i32 %y) {
; CHECK-LABEL: @test6( ; CHECK-LABEL: @test6(
; CHECK-NEXT: [[COND:%.*]] = select i1 [[C:%.*]], i32 7, i32 [[X:%.*]] ; CHECK-NEXT: [[COND:%.*]] = select i1 [[C:%.*]], i32 7, i32 [[X:%.*]]
; CHECK-NEXT: [[AND:%.*]] = and i32 [[COND]], [[X]] ; CHECK-NEXT: [[AND:%.*]] = and i32 [[COND]], [[X]]
; CHECK-NEXT: ret i32 [[AND]] ; CHECK-NEXT: ret i32 [[AND]]
; ;
%cond = select i1 %c, i32 7, i32 %x %cond = select i1 %c, i32 7, i32 %x
%and = and i32 %cond, %x %and = and i32 %cond, %x
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