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llvm-project/llvm/test/Transforms/InstSimplify/assume.ll

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[InstSimplify] regenerate checks using a script I didn't notice any significant changes in the actual checks here; all of these tests already used FileCheck, so a script can batch update them in one shot. This commit is just to show the value of automating this process: We have uniform formatting as opposed to a mish-mash of check structure that changes based on individual prefs and the current fashion. This makes it simpler to update when we find a bug or make an enhancement. llvm-svn: 264457
2016-03-26 04:12:25 +08:00
; NOTE: Assertions have been autogenerated by update_test_checks.py
[ValueTracking] emit a remark when we detect a conflicting assumption (PR31809) This is a follow-up to D29395 where we try to be good citizens and let the user know that we've probably gone off the rails. This should allow us to resolve: https://llvm.org/bugs/show_bug.cgi?id=31809 Differential Revision: https://reviews.llvm.org/D29404 llvm-svn: 294208
2017-02-07 02:26:06 +08:00
; RUN: opt -instsimplify -S < %s 2>&1 -pass-remarks-analysis=.* | FileCheck %s
; Verify that warnings are emitted for the 2nd and 3rd tests.
; CHECK: remark: /tmp/s.c:1:13: Detected conflicting code assumptions.
; CHECK: remark: /tmp/s.c:4:10: Detected conflicting code assumptions.
Add @llvm.assume, lowering, and some basic properties This is the first commit in a series that add an @llvm.assume intrinsic which can be used to provide the optimizer with a condition it may assume to be true (when the control flow would hit the intrinsic call). Some basic properties are added here: - llvm.invariant(true) is dead. - llvm.invariant(false) is unreachable (this directly corresponds to the documented behavior of MSVC's __assume(0)), so is llvm.invariant(undef). The intrinsic is tagged as writing arbitrarily, in order to maintain control dependencies. BasicAA has been updated, however, to return NoModRef for any particular location-based query so that we don't unnecessarily block code motion. llvm-svn: 213973
2014-07-26 05:13:35 +08:00
define void @test1() {
[InstSimplify] regenerate checks using a script I didn't notice any significant changes in the actual checks here; all of these tests already used FileCheck, so a script can batch update them in one shot. This commit is just to show the value of automating this process: We have uniform formatting as opposed to a mish-mash of check structure that changes based on individual prefs and the current fashion. This makes it simpler to update when we find a bug or make an enhancement. llvm-svn: 264457
2016-03-26 04:12:25 +08:00
; CHECK-LABEL: @test1(
; CHECK: ret void
;
Add @llvm.assume, lowering, and some basic properties This is the first commit in a series that add an @llvm.assume intrinsic which can be used to provide the optimizer with a condition it may assume to be true (when the control flow would hit the intrinsic call). Some basic properties are added here: - llvm.invariant(true) is dead. - llvm.invariant(false) is unreachable (this directly corresponds to the documented behavior of MSVC's __assume(0)), so is llvm.invariant(undef). The intrinsic is tagged as writing arbitrarily, in order to maintain control dependencies. BasicAA has been updated, however, to return NoModRef for any particular location-based query so that we don't unnecessarily block code motion. llvm-svn: 213973
2014-07-26 05:13:35 +08:00
call void @llvm.assume(i1 1)
ret void
}
[ValueTracking] avoid crashing from bad assumptions (PR31809) A program may contain llvm.assume info that disagrees with other analysis. This may be caused by UB in the program, so we must not crash because of that. As noted in the code comments: https://llvm.org/bugs/show_bug.cgi?id=31809 ...we can do better, but this at least avoids the assert/crash in the bug report. Differential Revision: https://reviews.llvm.org/D29395 llvm-svn: 293773
2017-02-01 23:41:32 +08:00
; The alloca guarantees that the low bits of %a are zero because of alignment.
; The assume says the opposite. The assume is processed last, so that's the
; return value. There's no way to win (we can't undo transforms that happened
; based on half-truths), so just don't crash.
[ValueTracking] emit a remark when we detect a conflicting assumption (PR31809) This is a follow-up to D29395 where we try to be good citizens and let the user know that we've probably gone off the rails. This should allow us to resolve: https://llvm.org/bugs/show_bug.cgi?id=31809 Differential Revision: https://reviews.llvm.org/D29404 llvm-svn: 294208
2017-02-07 02:26:06 +08:00
define i64 @PR31809() !dbg !7 {
[ValueTracking] avoid crashing from bad assumptions (PR31809) A program may contain llvm.assume info that disagrees with other analysis. This may be caused by UB in the program, so we must not crash because of that. As noted in the code comments: https://llvm.org/bugs/show_bug.cgi?id=31809 ...we can do better, but this at least avoids the assert/crash in the bug report. Differential Revision: https://reviews.llvm.org/D29395 llvm-svn: 293773
2017-02-01 23:41:32 +08:00
; CHECK-LABEL: @PR31809(
; CHECK-NEXT: ret i64 3
;
%a = alloca i32
[ValueTracking] emit a remark when we detect a conflicting assumption (PR31809) This is a follow-up to D29395 where we try to be good citizens and let the user know that we've probably gone off the rails. This should allow us to resolve: https://llvm.org/bugs/show_bug.cgi?id=31809 Differential Revision: https://reviews.llvm.org/D29404 llvm-svn: 294208
2017-02-07 02:26:06 +08:00
%t1 = ptrtoint i32* %a to i64, !dbg !9
[ValueTracking] avoid crashing from bad assumptions (PR31809) A program may contain llvm.assume info that disagrees with other analysis. This may be caused by UB in the program, so we must not crash because of that. As noted in the code comments: https://llvm.org/bugs/show_bug.cgi?id=31809 ...we can do better, but this at least avoids the assert/crash in the bug report. Differential Revision: https://reviews.llvm.org/D29395 llvm-svn: 293773
2017-02-01 23:41:32 +08:00
%cond = icmp eq i64 %t1, 3
call void @llvm.assume(i1 %cond)
ret i64 %t1
}
; Similar to above: there's no way to know which assumption is truthful,
; so just don't crash. The second icmp+assume gets processed later, so that
[ValueTracking] remove a FIXME for something we don't want to do; NFC The comment was added with: https://reviews.llvm.org/rL293773 ...but there would be a cost to implement this and possibly no payoff. llvm-svn: 293823
2017-02-02 06:27:34 +08:00
; determines the return value.
[ValueTracking] avoid crashing from bad assumptions (PR31809) A program may contain llvm.assume info that disagrees with other analysis. This may be caused by UB in the program, so we must not crash because of that. As noted in the code comments: https://llvm.org/bugs/show_bug.cgi?id=31809 ...we can do better, but this at least avoids the assert/crash in the bug report. Differential Revision: https://reviews.llvm.org/D29395 llvm-svn: 293773
2017-02-01 23:41:32 +08:00
[ValueTracking] emit a remark when we detect a conflicting assumption (PR31809) This is a follow-up to D29395 where we try to be good citizens and let the user know that we've probably gone off the rails. This should allow us to resolve: https://llvm.org/bugs/show_bug.cgi?id=31809 Differential Revision: https://reviews.llvm.org/D29404 llvm-svn: 294208
2017-02-07 02:26:06 +08:00
define i8 @conflicting_assumptions(i8 %x) !dbg !10 {
[ValueTracking] avoid crashing from bad assumptions (PR31809) A program may contain llvm.assume info that disagrees with other analysis. This may be caused by UB in the program, so we must not crash because of that. As noted in the code comments: https://llvm.org/bugs/show_bug.cgi?id=31809 ...we can do better, but this at least avoids the assert/crash in the bug report. Differential Revision: https://reviews.llvm.org/D29395 llvm-svn: 293773
2017-02-01 23:41:32 +08:00
; CHECK-LABEL: @conflicting_assumptions(
; CHECK-NEXT: call void @llvm.assume(i1 false)
; CHECK-NEXT: [[COND2:%.*]] = icmp eq i8 %x, 4
; CHECK-NEXT: call void @llvm.assume(i1 [[COND2]])
; CHECK-NEXT: ret i8 5
;
[ValueTracking] emit a remark when we detect a conflicting assumption (PR31809) This is a follow-up to D29395 where we try to be good citizens and let the user know that we've probably gone off the rails. This should allow us to resolve: https://llvm.org/bugs/show_bug.cgi?id=31809 Differential Revision: https://reviews.llvm.org/D29404 llvm-svn: 294208
2017-02-07 02:26:06 +08:00
%add = add i8 %x, 1, !dbg !11
[ValueTracking] avoid crashing from bad assumptions (PR31809) A program may contain llvm.assume info that disagrees with other analysis. This may be caused by UB in the program, so we must not crash because of that. As noted in the code comments: https://llvm.org/bugs/show_bug.cgi?id=31809 ...we can do better, but this at least avoids the assert/crash in the bug report. Differential Revision: https://reviews.llvm.org/D29395 llvm-svn: 293773
2017-02-01 23:41:32 +08:00
%cond1 = icmp eq i8 %x, 3
call void @llvm.assume(i1 %cond1)
%cond2 = icmp eq i8 %x, 4
call void @llvm.assume(i1 %cond2)
ret i8 %add
}
Add @llvm.assume, lowering, and some basic properties This is the first commit in a series that add an @llvm.assume intrinsic which can be used to provide the optimizer with a condition it may assume to be true (when the control flow would hit the intrinsic call). Some basic properties are added here: - llvm.invariant(true) is dead. - llvm.invariant(false) is unreachable (this directly corresponds to the documented behavior of MSVC's __assume(0)), so is llvm.invariant(undef). The intrinsic is tagged as writing arbitrarily, in order to maintain control dependencies. BasicAA has been updated, however, to return NoModRef for any particular location-based query so that we don't unnecessarily block code motion. llvm-svn: 213973
2014-07-26 05:13:35 +08:00
declare void @llvm.assume(i1) nounwind
[ValueTracking] emit a remark when we detect a conflicting assumption (PR31809) This is a follow-up to D29395 where we try to be good citizens and let the user know that we've probably gone off the rails. This should allow us to resolve: https://llvm.org/bugs/show_bug.cgi?id=31809 Differential Revision: https://reviews.llvm.org/D29404 llvm-svn: 294208
2017-02-07 02:26:06 +08:00
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5}
!llvm.ident = !{!6}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 4.0.0 (trunk 282540) (llvm/trunk 282542)", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly, enums: !2)
!1 = !DIFile(filename: "/tmp/s.c", directory: "/tmp")
!2 = !{}
!3 = !{i32 2, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"PIC Level", i32 2}
!6 = !{!"clang version 4.0.0 (trunk 282540) (llvm/trunk 282542)"}
!7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, variables: !2)
!8 = !DISubroutineType(types: !2)
!9 = !DILocation(line: 1, column: 13, scope: !7)
!10 = distinct !DISubprogram(name: "bar", scope: !1, file: !1, line: 3, type: !8, isLocal: false, isDefinition: true, scopeLine: 3, isOptimized: true, unit: !0, variables: !2)
!11 = !DILocation(line: 4, column: 10, scope: !10)
!12 = !DILocation(line: 4, column: 3, scope: !10)