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Differential D45107

[InstCombine] [NFC] Add tests for getting rid of select of bittest (PR36950 / PR17564)
ClosedPublic

Authored by lebedev.ri on Mar 30 2018, 2:22 PM.

Details

Reviewers
spatel
craig.topper
Commits
rGc0c9ba7ee04a: [InstCombine] [NFC] Add tests for getting rid of select of bittest (PR36950 /…
rL329198: [InstCombine] [NFC] Add tests for getting rid of select of bittest (PR36950 /…
Summary

See PR36950, PR17564, D45065, D45108

Diff Detail

Repository
rL LLVM

Event Timeline

lebedev.ri created this revision.Mar 30 2018, 2:22 PM
lebedev.ri mentioned this in D45108: [InstCombine] Get rid of select of bittest (PR36950 / PR17564).Mar 30 2018, 2:29 PM
lebedev.ri added a child revision: D45108: [InstCombine] Get rid of select of bittest (PR36950 / PR17564).
lebedev.ri edited the summary of this revision. (Show Details)
lebedev.ri updated this revision to Diff 140530.Mar 31 2018, 3:30 AM

Deduplicate tests, improve test coverage.

lebedev.ri updated this revision to Diff 140538.Mar 31 2018, 7:57 AM

Add tests with non-splat constant vectors.

spatel added inline comments.Apr 3 2018, 12:56 PM
test/Transforms/InstCombine/select-of-bittest.ll
448–451

This is testing that some other folds work as expected, so it doesn't really belong here IMO.

468

Similar to @n9, I'd remove this test because the pattern shouldn't survive as-is before we get to the select.

The comment isn't correct - shifting by the bit-width produces a poison value.

lebedev.ri updated this revision to Diff 140954.Apr 4 2018, 6:36 AM
lebedev.ri marked 2 inline comments as done.

Drop two unneeded negative tests.

spatel accepted this revision.Apr 4 2018, 6:45 AM

LGTM.

This revision is now accepted and ready to land.Apr 4 2018, 6:45 AM
Closed by commit rL329198: [InstCombine] [NFC] Add tests for getting rid of select of bittest (PR36950 /… (authored by lebedevri). · Explain WhyApr 4 2018, 7:15 AM
This revision was automatically updated to reflect the committed changes.
Diffusion mentioned this in rL329492: [InstCombine] Get rid of select of bittest (PR36950 / PR17564).Apr 7 2018, 3:40 AM

Revision Contents

PathSize
test/
Transforms/
InstCombine/
407 lines

Diff 140530

test/Transforms/InstCombine/select-of-bittest.ll

  • This file was added.
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
; https://bugs.llvm.org/show_bug.cgi?id=36950
; These all should be just and+icmp, there should be no select.
; https://rise4fun.com/Alive/uiH
define i32 @and_lshr_and(i32) {
; CHECK-LABEL: @and_lshr_and(
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP0:%.*]], 1
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i32 [[TMP2]], 0
; CHECK-NEXT: [[TMP4:%.*]] = lshr i32 [[TMP0]], 1
; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[TMP4]], 1
; CHECK-NEXT: [[TMP6:%.*]] = select i1 [[TMP3]], i32 [[TMP5]], i32 1
; CHECK-NEXT: ret i32 [[TMP6]]
;
%2 = and i32 %0, 1
%3 = icmp eq i32 %2, 0
%4 = lshr i32 %0, 1
%5 = and i32 %4, 1
%6 = select i1 %3, i32 %5, i32 1
ret i32 %6
}
define <2 x i32> @and_lshr_and_vec(<2 x i32>) {
; CHECK-LABEL: @and_lshr_and_vec(
; CHECK-NEXT: [[TMP2:%.*]] = and <2 x i32> [[TMP0:%.*]], <i32 1, i32 1>
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq <2 x i32> [[TMP2]], zeroinitializer
; CHECK-NEXT: [[TMP4:%.*]] = lshr <2 x i32> [[TMP0]], <i32 1, i32 1>
; CHECK-NEXT: [[TMP5:%.*]] = and <2 x i32> [[TMP4]], <i32 1, i32 1>
; CHECK-NEXT: [[TMP6:%.*]] = select <2 x i1> [[TMP3]], <2 x i32> [[TMP5]], <2 x i32> <i32 1, i32 1>
; CHECK-NEXT: ret <2 x i32> [[TMP6]]
;
%2 = and <2 x i32> %0, <i32 1, i32 1>
%3 = icmp eq <2 x i32> %2, <i32 0, i32 0>
%4 = lshr <2 x i32> %0, <i32 1, i32 1>
%5 = and <2 x i32> %4, <i32 1, i32 1>
%6 = select <2 x i1> %3, <2 x i32> %5, <2 x i32> <i32 1, i32 1>
ret <2 x i32> %6
}
define <3 x i32> @and_lshr_and_vec_undef(<3 x i32>) {
; CHECK-LABEL: @and_lshr_and_vec_undef(
; CHECK-NEXT: [[TMP2:%.*]] = and <3 x i32> [[TMP0:%.*]], <i32 1, i32 undef, i32 1>
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq <3 x i32> [[TMP2]], <i32 0, i32 undef, i32 0>
; CHECK-NEXT: [[TMP4:%.*]] = lshr <3 x i32> [[TMP0]], <i32 1, i32 undef, i32 1>
; CHECK-NEXT: [[TMP5:%.*]] = and <3 x i32> [[TMP4]], <i32 1, i32 undef, i32 1>
; CHECK-NEXT: [[TMP6:%.*]] = select <3 x i1> [[TMP3]], <3 x i32> [[TMP5]], <3 x i32> <i32 1, i32 undef, i32 1>
; CHECK-NEXT: ret <3 x i32> [[TMP6]]
;
%2 = and <3 x i32> %0, <i32 1, i32 undef, i32 1>
%3 = icmp eq <3 x i32> %2, <i32 0, i32 undef, i32 0>
%4 = lshr <3 x i32> %0, <i32 1, i32 undef, i32 1>
%5 = and <3 x i32> %4, <i32 1, i32 undef, i32 1>
%6 = select <3 x i1> %3, <3 x i32> %5, <3 x i32> <i32 1, i32 undef, i32 1>
ret <3 x i32> %6
}
define i32 @and_and(i32) {
; CHECK-LABEL: @and_and(
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP0:%.*]], 2
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i32 [[TMP2]], 0
; CHECK-NEXT: [[TMP4:%.*]] = and i32 [[TMP0]], 1
; CHECK-NEXT: [[TMP5:%.*]] = select i1 [[TMP3]], i32 [[TMP4]], i32 1
; CHECK-NEXT: ret i32 [[TMP5]]
;
%2 = and i32 %0, 2
%3 = icmp eq i32 %2, 0
%4 = and i32 %0, 1
%5 = select i1 %3, i32 %4, i32 1
ret i32 %5
}
define <2 x i32> @and_and_vec(<2 x i32>) {
; CHECK-LABEL: @and_and_vec(
; CHECK-NEXT: [[TMP2:%.*]] = and <2 x i32> [[TMP0:%.*]], <i32 2, i32 2>
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq <2 x i32> [[TMP2]], zeroinitializer
; CHECK-NEXT: [[TMP4:%.*]] = and <2 x i32> [[TMP0]], <i32 1, i32 1>
; CHECK-NEXT: [[TMP5:%.*]] = select <2 x i1> [[TMP3]], <2 x i32> [[TMP4]], <2 x i32> <i32 1, i32 1>
; CHECK-NEXT: ret <2 x i32> [[TMP5]]
;
%2 = and <2 x i32> %0, <i32 2, i32 2>
%3 = icmp eq <2 x i32> %2, <i32 0, i32 0>
%4 = and <2 x i32> %0, <i32 1, i32 1>
%5 = select <2 x i1> %3, <2 x i32> %4, <2 x i32> <i32 1, i32 1>
ret <2 x i32> %5
}
define <3 x i32> @and_and_vec_undef(<3 x i32>) {
; CHECK-LABEL: @and_and_vec_undef(
; CHECK-NEXT: [[TMP2:%.*]] = and <3 x i32> [[TMP0:%.*]], <i32 2, i32 undef, i32 2>
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq <3 x i32> [[TMP2]], <i32 0, i32 undef, i32 0>
; CHECK-NEXT: [[TMP4:%.*]] = and <3 x i32> [[TMP0]], <i32 1, i32 undef, i32 1>
; CHECK-NEXT: [[TMP5:%.*]] = select <3 x i1> [[TMP3]], <3 x i32> [[TMP4]], <3 x i32> <i32 1, i32 undef, i32 1>
; CHECK-NEXT: ret <3 x i32> [[TMP5]]
;
%2 = and <3 x i32> %0, <i32 2, i32 undef, i32 2>
%3 = icmp eq <3 x i32> %2, <i32 0, i32 undef, i32 0>
%4 = and <3 x i32> %0, <i32 1, i32 undef, i32 1>
%5 = select <3 x i1> %3, <3 x i32> %4, <3 x i32> <i32 1, i32 undef, i32 1>
ret <3 x i32> %5
}
; ============================================================================ ;
; Mask can be a variable, too.
; ============================================================================ ;
define i32 @f_var0(i32, i32) {
; CHECK-LABEL: @f_var0(
; CHECK-NEXT: [[TMP3:%.*]] = and i32 [[TMP0:%.*]], [[TMP1:%.*]]
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq i32 [[TMP3]], 0
; CHECK-NEXT: [[TMP5:%.*]] = lshr i32 [[TMP0]], 1
; CHECK-NEXT: [[TMP6:%.*]] = and i32 [[TMP5]], 1
; CHECK-NEXT: [[TMP7:%.*]] = select i1 [[TMP4]], i32 [[TMP6]], i32 1
; CHECK-NEXT: ret i32 [[TMP7]]
;
%3 = and i32 %0, %1
%4 = icmp eq i32 %3, 0
%5 = lshr i32 %0, 1
%6 = and i32 %5, 1
%7 = select i1 %4, i32 %6, i32 1
ret i32 %7
}
define <2 x i32> @f_var0_vec(<2 x i32>, <2 x i32>) {
; CHECK-LABEL: @f_var0_vec(
; CHECK-NEXT: [[TMP3:%.*]] = and <2 x i32> [[TMP0:%.*]], [[TMP1:%.*]]
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq <2 x i32> [[TMP3]], zeroinitializer
; CHECK-NEXT: [[TMP5:%.*]] = lshr <2 x i32> [[TMP0]], <i32 1, i32 1>
; CHECK-NEXT: [[TMP6:%.*]] = and <2 x i32> [[TMP5]], <i32 1, i32 1>
; CHECK-NEXT: [[TMP7:%.*]] = select <2 x i1> [[TMP4]], <2 x i32> [[TMP6]], <2 x i32> <i32 1, i32 1>
; CHECK-NEXT: ret <2 x i32> [[TMP7]]
;
%3 = and <2 x i32> %0, %1
%4 = icmp eq <2 x i32> %3, <i32 0, i32 0>
%5 = lshr <2 x i32> %0, <i32 1, i32 1>
%6 = and <2 x i32> %5, <i32 1, i32 1>
%7 = select <2 x i1> %4, <2 x i32> %6, <2 x i32> <i32 1, i32 1>
ret <2 x i32> %7
}
define <3 x i32> @f_var0_vec_undef(<3 x i32>, <3 x i32>) {
; CHECK-LABEL: @f_var0_vec_undef(
; CHECK-NEXT: [[TMP3:%.*]] = and <3 x i32> [[TMP0:%.*]], [[TMP1:%.*]]
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq <3 x i32> [[TMP3]], <i32 0, i32 undef, i32 0>
; CHECK-NEXT: [[TMP5:%.*]] = lshr <3 x i32> [[TMP0]], <i32 1, i32 undef, i32 1>
; CHECK-NEXT: [[TMP6:%.*]] = and <3 x i32> [[TMP5]], <i32 1, i32 undef, i32 1>
; CHECK-NEXT: [[TMP7:%.*]] = select <3 x i1> [[TMP4]], <3 x i32> [[TMP6]], <3 x i32> <i32 1, i32 undef, i32 1>
; CHECK-NEXT: ret <3 x i32> [[TMP7]]
;
%3 = and <3 x i32> %0, %1
%4 = icmp eq <3 x i32> %3, <i32 0, i32 undef, i32 0>
%5 = lshr <3 x i32> %0, <i32 1, i32 undef, i32 1>
%6 = and <3 x i32> %5, <i32 1, i32 undef, i32 1>
%7 = select <3 x i1> %4, <3 x i32> %6, <3 x i32> <i32 1, i32 undef, i32 1>
ret <3 x i32> %7
}
define i32 @f_var1(i32, i32) {
; CHECK-LABEL: @f_var1(
; CHECK-NEXT: [[TMP3:%.*]] = and i32 [[TMP0:%.*]], [[TMP1:%.*]]
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq i32 [[TMP3]], 0
; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[TMP0]], 1
; CHECK-NEXT: [[TMP6:%.*]] = select i1 [[TMP4]], i32 [[TMP5]], i32 1
; CHECK-NEXT: ret i32 [[TMP6]]
;
%3 = and i32 %0, %1
%4 = icmp eq i32 %3, 0
%5 = and i32 %0, 1
%6 = select i1 %4, i32 %5, i32 1
ret i32 %6
}
define <2 x i32> @f_var1_vec(<2 x i32>, <2 x i32>) {
; CHECK-LABEL: @f_var1_vec(
; CHECK-NEXT: [[TMP3:%.*]] = and <2 x i32> [[TMP0:%.*]], [[TMP1:%.*]]
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq <2 x i32> [[TMP3]], zeroinitializer
; CHECK-NEXT: [[TMP5:%.*]] = and <2 x i32> [[TMP0]], <i32 1, i32 1>
; CHECK-NEXT: [[TMP6:%.*]] = select <2 x i1> [[TMP4]], <2 x i32> [[TMP5]], <2 x i32> <i32 1, i32 1>
; CHECK-NEXT: ret <2 x i32> [[TMP6]]
;
%3 = and <2 x i32> %0, %1
%4 = icmp eq <2 x i32> %3, <i32 0, i32 0>
%5 = and <2 x i32> %0, <i32 1, i32 1>
%6 = select <2 x i1> %4, <2 x i32> %5, <2 x i32> <i32 1, i32 1>
ret <2 x i32> %6
}
define <3 x i32> @f_var1_vec_undef(<3 x i32>, <3 x i32>) {
; CHECK-LABEL: @f_var1_vec_undef(
; CHECK-NEXT: [[TMP3:%.*]] = and <3 x i32> [[TMP0:%.*]], [[TMP1:%.*]]
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq <3 x i32> [[TMP3]], <i32 0, i32 undef, i32 0>
; CHECK-NEXT: [[TMP5:%.*]] = and <3 x i32> [[TMP0]], <i32 1, i32 undef, i32 1>
; CHECK-NEXT: [[TMP6:%.*]] = select <3 x i1> [[TMP4]], <3 x i32> [[TMP5]], <3 x i32> <i32 1, i32 undef, i32 1>
; CHECK-NEXT: ret <3 x i32> [[TMP6]]
;
%3 = and <3 x i32> %0, %1
%4 = icmp eq <3 x i32> %3, <i32 0, i32 undef, i32 0>
%5 = and <3 x i32> %0, <i32 1, i32 undef, i32 1>
%6 = select <3 x i1> %4, <3 x i32> %5, <3 x i32> <i32 1, i32 undef, i32 1>
ret <3 x i32> %6
}
; ============================================================================ ;
; Negative tests. Should not be folded.
; ============================================================================ ;
; Different variables are used
define i32 @n0(i32, i32) {
; CHECK-LABEL: @n0(
; CHECK-NEXT: [[TMP3:%.*]] = and i32 [[TMP0:%.*]], 1
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq i32 [[TMP3]], 0
; CHECK-NEXT: [[TMP5:%.*]] = lshr i32 [[TMP1:%.*]], 1
; CHECK-NEXT: [[TMP6:%.*]] = and i32 [[TMP5]], 1
; CHECK-NEXT: [[TMP7:%.*]] = select i1 [[TMP4]], i32 [[TMP6]], i32 1
; CHECK-NEXT: ret i32 [[TMP7]]
;
%3 = and i32 %0, 1
%4 = icmp eq i32 %3, 0
%5 = lshr i32 %1, 1 ; works on %1 instead of %0
%6 = and i32 %5, 1
%7 = select i1 %4, i32 %6, i32 1
ret i32 %7
}
define i32 @n1(i32, i32) {
; CHECK-LABEL: @n1(
; CHECK-NEXT: [[TMP3:%.*]] = and i32 [[TMP0:%.*]], 2
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq i32 [[TMP3]], 0
; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[TMP1:%.*]], 1
; CHECK-NEXT: [[TMP6:%.*]] = select i1 [[TMP4]], i32 [[TMP5]], i32 1
; CHECK-NEXT: ret i32 [[TMP6]]
;
%3 = and i32 %0, 2
%4 = icmp eq i32 %3, 0
%5 = and i32 %1, 1 ; works on %1 instead of %0
%6 = select i1 %4, i32 %5, i32 1
ret i32 %6
}
; False-value is not 1
define i32 @n2(i32) {
; CHECK-LABEL: @n2(
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP0:%.*]], 1
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i32 [[TMP2]], 0
; CHECK-NEXT: [[TMP4:%.*]] = lshr i32 [[TMP0]], 2
; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[TMP4]], 1
; CHECK-NEXT: [[TMP6:%.*]] = select i1 [[TMP3]], i32 [[TMP5]], i32 0
; CHECK-NEXT: ret i32 [[TMP6]]
;
%2 = and i32 %0, 1
%3 = icmp eq i32 %2, 0
%4 = lshr i32 %0, 2
%5 = and i32 %4, 1
%6 = select i1 %3, i32 %5, i32 0 ; 0 instead of 1
ret i32 %6
}
define i32 @n3(i32) {
; CHECK-LABEL: @n3(
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP0:%.*]], 2
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i32 [[TMP2]], 0
; CHECK-NEXT: [[TMP4:%.*]] = and i32 [[TMP0]], 1
; CHECK-NEXT: [[TMP5:%.*]] = select i1 [[TMP3]], i32 [[TMP4]], i32 0
; CHECK-NEXT: ret i32 [[TMP5]]
;
%2 = and i32 %0, 2
%3 = icmp eq i32 %2, 0
%4 = and i32 %0, 1
%5 = select i1 %3, i32 %4, i32 0 ; 0 instead of 1
ret i32 %5
}
; Mask of second and is not one
define i32 @n4(i32) {
; CHECK-LABEL: @n4(
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP0:%.*]], 1
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i32 [[TMP2]], 0
; CHECK-NEXT: [[TMP4:%.*]] = lshr i32 [[TMP0]], 2
; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[TMP4]], 2
; CHECK-NEXT: [[TMP6:%.*]] = select i1 [[TMP3]], i32 [[TMP5]], i32 1
; CHECK-NEXT: ret i32 [[TMP6]]
;
%2 = and i32 %0, 1
%3 = icmp eq i32 %2, 0
%4 = lshr i32 %0, 2
%5 = and i32 %4, 2 ; 2 instead of 1
%6 = select i1 %3, i32 %5, i32 1
ret i32 %6
}
define i32 @n5(i32) {
; CHECK-LABEL: @n5(
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP0:%.*]], 2
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i32 [[TMP2]], 0
; CHECK-NEXT: [[TMP4:%.*]] = and i32 [[TMP0]], 2
; CHECK-NEXT: [[TMP5:%.*]] = select i1 [[TMP3]], i32 [[TMP4]], i32 1
; CHECK-NEXT: ret i32 [[TMP5]]
;
%2 = and i32 %0, 2
%3 = icmp eq i32 %2, 0
%4 = and i32 %0, 2 ; 2 instead of 1
%5 = select i1 %3, i32 %4, i32 1
ret i32 %5
}
; Wrong icmp pred
define i32 @n6(i32) {
; CHECK-LABEL: @n6(
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP0:%.*]], 1
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i32 [[TMP2]], 0
; CHECK-NEXT: [[TMP4:%.*]] = lshr i32 [[TMP0]], 2
; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[TMP4]], 1
; CHECK-NEXT: [[TMP6:%.*]] = select i1 [[TMP3]], i32 1, i32 [[TMP5]]
; CHECK-NEXT: ret i32 [[TMP6]]
;
%2 = and i32 %0, 1
%3 = icmp ne i32 %2, 0 ; ne, not eq
%4 = lshr i32 %0, 2
%5 = and i32 %4, 1
%6 = select i1 %3, i32 %5, i32 1
ret i32 %6
}
define i32 @n7(i32) {
; CHECK-LABEL: @n7(
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP0:%.*]], 2
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i32 [[TMP2]], 0
; CHECK-NEXT: [[TMP4:%.*]] = and i32 [[TMP0]], 1
; CHECK-NEXT: [[TMP5:%.*]] = select i1 [[TMP3]], i32 1, i32 [[TMP4]]
; CHECK-NEXT: ret i32 [[TMP5]]
;
%2 = and i32 %0, 2
%3 = icmp ne i32 %2, 0 ; ne, not eq
%4 = and i32 %0, 1
%5 = select i1 %3, i32 %4, i32 1
ret i32 %5
}
; icmp second operand is not zero
define i32 @n8(i32) {
; CHECK-LABEL: @n8(
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP0:%.*]], 1
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i32 [[TMP2]], 0
; CHECK-NEXT: [[TMP4:%.*]] = lshr i32 [[TMP0]], 2
; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[TMP4]], 1
; CHECK-NEXT: [[TMP6:%.*]] = select i1 [[TMP3]], i32 1, i32 [[TMP5]]
; CHECK-NEXT: ret i32 [[TMP6]]
;
%2 = and i32 %0, 1
%3 = icmp eq i32 %2, 1 ; 1, not 0
%4 = lshr i32 %0, 2
%5 = and i32 %4, 1
%6 = select i1 %3, i32 %5, i32 1
ret i32 %6
}
define i32 @n9(i32) {
; CHECK-LABEL: @n9(
; CHECK-NEXT: ret i32 1
;
%2 = and i32 %0, 2
%3 = icmp eq i32 %2, 1 ; 1, not 0
%4 = and i32 %0, 1
%5 = select i1 %3, i32 %4, i32 1
ret i32 %5
}
; Bad shift
define i32 @n10(i32) {
; CHECK-LABEL: @n10(
; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP0:%.*]], 1
; CHECK-NEXT: ret i32 [[TMP2]]
;
%2 = and i32 %0, 1
%3 = icmp eq i32 %2, 0
%4 = lshr i32 %0, 32 ; shifting by 32 leaves no bits
%5 = and i32 %4, 1
%6 = select i1 %3, i32 %5, i32 1
ret i32 %6
}
; Shift not by a constant
define i32 @n11(i32, i32) {
; CHECK-LABEL: @n11(
; CHECK-NEXT: [[TMP3:%.*]] = and i32 [[TMP0:%.*]], 1
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq i32 [[TMP3]], 0
; CHECK-NEXT: [[TMP5:%.*]] = lshr i32 [[TMP0]], [[TMP1:%.*]]
; CHECK-NEXT: [[TMP6:%.*]] = and i32 [[TMP5]], 1
; CHECK-NEXT: [[TMP7:%.*]] = select i1 [[TMP4]], i32 [[TMP6]], i32 1
; CHECK-NEXT: ret i32 [[TMP7]]
;
%3 = and i32 %0, 1
%4 = icmp eq i32 %3, 0
%5 = lshr i32 %0, %1 ; %1, should be a constant
%6 = and i32 %5, 1
%7 = select i1 %4, i32 %6, i32 1
ret i32 %7
}
spatelUnsubmitted
Done
ReplyInline Actions

This is testing that some other folds work as expected, so it doesn't really belong here IMO.

spatel: This is testing that some other folds work as expected, so it doesn't really belong here IMO.
spatelUnsubmitted
Done
ReplyInline Actions

Similar to @n9, I'd remove this test because the pattern shouldn't survive as-is before we get to the select.

The comment isn't correct - shifting by the bit-width produces a poison value.

spatel: Similar to @n9, I'd remove this test because the pattern shouldn't survive as-is before we get…