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llvm-project/llvm/test/Transforms/DeadStoreElimination/inst-limits.ll

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Fixing a heisenbug where the memory dependence analysis behaves differently with and without -g. Adding a test case to make sure that the threshold used in the memory dependence analysis is respected. The test case also checks that debug intrinsics are not counted towards this threshold. Differential Revision: http://llvm-reviews.chandlerc.com/D2141 llvm-svn: 194646
2013-11-14 09:10:52 +08:00
; RUN: opt -S -dse < %s | FileCheck %s
; If there are two stores to the same location, DSE should be able to remove
; the first store if the two stores are separated by no more than 98
; instructions. The existence of debug intrinsics between the stores should
; not affect this instruction limit.
@x = global i32 0, align 4
; Function Attrs: nounwind
define i32 @test_within_limit() {
entry:
; The first store; later there is a second store to the same location,
; so this store should be optimized away by DSE.
; CHECK-NOT: store i32 1, i32* @x, align 4
store i32 1, i32* @x, align 4
; Insert 98 dummy instructions between the two stores
%0 = bitcast i32 0 to i32
%1 = bitcast i32 0 to i32
%2 = bitcast i32 0 to i32
%3 = bitcast i32 0 to i32
%4 = bitcast i32 0 to i32
%5 = bitcast i32 0 to i32
%6 = bitcast i32 0 to i32
%7 = bitcast i32 0 to i32
%8 = bitcast i32 0 to i32
%9 = bitcast i32 0 to i32
%10 = bitcast i32 0 to i32
%11 = bitcast i32 0 to i32
%12 = bitcast i32 0 to i32
%13 = bitcast i32 0 to i32
%14 = bitcast i32 0 to i32
%15 = bitcast i32 0 to i32
%16 = bitcast i32 0 to i32
%17 = bitcast i32 0 to i32
%18 = bitcast i32 0 to i32
%19 = bitcast i32 0 to i32
%20 = bitcast i32 0 to i32
%21 = bitcast i32 0 to i32
%22 = bitcast i32 0 to i32
%23 = bitcast i32 0 to i32
%24 = bitcast i32 0 to i32
%25 = bitcast i32 0 to i32
%26 = bitcast i32 0 to i32
%27 = bitcast i32 0 to i32
%28 = bitcast i32 0 to i32
%29 = bitcast i32 0 to i32
%30 = bitcast i32 0 to i32
%31 = bitcast i32 0 to i32
%32 = bitcast i32 0 to i32
%33 = bitcast i32 0 to i32
%34 = bitcast i32 0 to i32
%35 = bitcast i32 0 to i32
%36 = bitcast i32 0 to i32
%37 = bitcast i32 0 to i32
%38 = bitcast i32 0 to i32
%39 = bitcast i32 0 to i32
%40 = bitcast i32 0 to i32
%41 = bitcast i32 0 to i32
%42 = bitcast i32 0 to i32
%43 = bitcast i32 0 to i32
%44 = bitcast i32 0 to i32
%45 = bitcast i32 0 to i32
%46 = bitcast i32 0 to i32
%47 = bitcast i32 0 to i32
%48 = bitcast i32 0 to i32
%49 = bitcast i32 0 to i32
%50 = bitcast i32 0 to i32
%51 = bitcast i32 0 to i32
%52 = bitcast i32 0 to i32
%53 = bitcast i32 0 to i32
%54 = bitcast i32 0 to i32
%55 = bitcast i32 0 to i32
%56 = bitcast i32 0 to i32
%57 = bitcast i32 0 to i32
%58 = bitcast i32 0 to i32
%59 = bitcast i32 0 to i32
%60 = bitcast i32 0 to i32
%61 = bitcast i32 0 to i32
%62 = bitcast i32 0 to i32
%63 = bitcast i32 0 to i32
%64 = bitcast i32 0 to i32
%65 = bitcast i32 0 to i32
%66 = bitcast i32 0 to i32
%67 = bitcast i32 0 to i32
%68 = bitcast i32 0 to i32
%69 = bitcast i32 0 to i32
%70 = bitcast i32 0 to i32
%71 = bitcast i32 0 to i32
%72 = bitcast i32 0 to i32
%73 = bitcast i32 0 to i32
%74 = bitcast i32 0 to i32
%75 = bitcast i32 0 to i32
%76 = bitcast i32 0 to i32
%77 = bitcast i32 0 to i32
%78 = bitcast i32 0 to i32
%79 = bitcast i32 0 to i32
%80 = bitcast i32 0 to i32
%81 = bitcast i32 0 to i32
%82 = bitcast i32 0 to i32
%83 = bitcast i32 0 to i32
%84 = bitcast i32 0 to i32
%85 = bitcast i32 0 to i32
%86 = bitcast i32 0 to i32
%87 = bitcast i32 0 to i32
%88 = bitcast i32 0 to i32
%89 = bitcast i32 0 to i32
%90 = bitcast i32 0 to i32
%91 = bitcast i32 0 to i32
%92 = bitcast i32 0 to i32
%93 = bitcast i32 0 to i32
%94 = bitcast i32 0 to i32
%95 = bitcast i32 0 to i32
%96 = bitcast i32 0 to i32
%97 = bitcast i32 0 to i32
; Insert a meaningless dbg.value intrinsic; it should have no
; effect on the working of DSE in any way.
Move the complex address expression out of DIVariable and into an extra argument of the llvm.dbg.declare/llvm.dbg.value intrinsics. Previously, DIVariable was a variable-length field that has an optional reference to a Metadata array consisting of a variable number of complex address expressions. In the case of OpPiece expressions this is wasting a lot of storage in IR, because when an aggregate type is, e.g., SROA'd into all of its n individual members, the IR will contain n copies of the DIVariable, all alike, only differing in the complex address reference at the end. By making the complex address into an extra argument of the dbg.value/dbg.declare intrinsics, all of the pieces can reference the same variable and the complex address expressions can be uniqued across the CU, too. Down the road, this will allow us to move other flags, such as "indirection" out of the DIVariable, too. The new intrinsics look like this: declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr) declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr) This patch adds a new LLVM-local tag to DIExpressions, so we can detect and pretty-print DIExpression metadata nodes. What this patch doesn't do: This patch does not touch the "Indirect" field in DIVariable; but moving that into the expression would be a natural next step. http://reviews.llvm.org/D4919 rdar://problem/17994491 Thanks to dblaikie and dexonsmith for reviewing this patch! Note: I accidentally committed a bogus older version of this patch previously. llvm-svn: 218787
2014-10-02 02:55:02 +08:00
call void @llvm.dbg.value(metadata !12, i64 0, metadata !10, metadata !{})
Fixing a heisenbug where the memory dependence analysis behaves differently with and without -g. Adding a test case to make sure that the threshold used in the memory dependence analysis is respected. The test case also checks that debug intrinsics are not counted towards this threshold. Differential Revision: http://llvm-reviews.chandlerc.com/D2141 llvm-svn: 194646
2013-11-14 09:10:52 +08:00
; CHECK: store i32 -1, i32* @x, align 4
store i32 -1, i32* @x, align 4
ret i32 0
}
; Function Attrs: nounwind
define i32 @test_outside_limit() {
entry:
; The first store; later there is a second store to the same location
; CHECK: store i32 1, i32* @x, align 4
store i32 1, i32* @x, align 4
; Insert 99 dummy instructions between the two stores; this is
; one too many instruction for the DSE to take place.
%0 = bitcast i32 0 to i32
%1 = bitcast i32 0 to i32
%2 = bitcast i32 0 to i32
%3 = bitcast i32 0 to i32
%4 = bitcast i32 0 to i32
%5 = bitcast i32 0 to i32
%6 = bitcast i32 0 to i32
%7 = bitcast i32 0 to i32
%8 = bitcast i32 0 to i32
%9 = bitcast i32 0 to i32
%10 = bitcast i32 0 to i32
%11 = bitcast i32 0 to i32
%12 = bitcast i32 0 to i32
%13 = bitcast i32 0 to i32
%14 = bitcast i32 0 to i32
%15 = bitcast i32 0 to i32
%16 = bitcast i32 0 to i32
%17 = bitcast i32 0 to i32
%18 = bitcast i32 0 to i32
%19 = bitcast i32 0 to i32
%20 = bitcast i32 0 to i32
%21 = bitcast i32 0 to i32
%22 = bitcast i32 0 to i32
%23 = bitcast i32 0 to i32
%24 = bitcast i32 0 to i32
%25 = bitcast i32 0 to i32
%26 = bitcast i32 0 to i32
%27 = bitcast i32 0 to i32
%28 = bitcast i32 0 to i32
%29 = bitcast i32 0 to i32
%30 = bitcast i32 0 to i32
%31 = bitcast i32 0 to i32
%32 = bitcast i32 0 to i32
%33 = bitcast i32 0 to i32
%34 = bitcast i32 0 to i32
%35 = bitcast i32 0 to i32
%36 = bitcast i32 0 to i32
%37 = bitcast i32 0 to i32
%38 = bitcast i32 0 to i32
%39 = bitcast i32 0 to i32
%40 = bitcast i32 0 to i32
%41 = bitcast i32 0 to i32
%42 = bitcast i32 0 to i32
%43 = bitcast i32 0 to i32
%44 = bitcast i32 0 to i32
%45 = bitcast i32 0 to i32
%46 = bitcast i32 0 to i32
%47 = bitcast i32 0 to i32
%48 = bitcast i32 0 to i32
%49 = bitcast i32 0 to i32
%50 = bitcast i32 0 to i32
%51 = bitcast i32 0 to i32
%52 = bitcast i32 0 to i32
%53 = bitcast i32 0 to i32
%54 = bitcast i32 0 to i32
%55 = bitcast i32 0 to i32
%56 = bitcast i32 0 to i32
%57 = bitcast i32 0 to i32
%58 = bitcast i32 0 to i32
%59 = bitcast i32 0 to i32
%60 = bitcast i32 0 to i32
%61 = bitcast i32 0 to i32
%62 = bitcast i32 0 to i32
%63 = bitcast i32 0 to i32
%64 = bitcast i32 0 to i32
%65 = bitcast i32 0 to i32
%66 = bitcast i32 0 to i32
%67 = bitcast i32 0 to i32
%68 = bitcast i32 0 to i32
%69 = bitcast i32 0 to i32
%70 = bitcast i32 0 to i32
%71 = bitcast i32 0 to i32
%72 = bitcast i32 0 to i32
%73 = bitcast i32 0 to i32
%74 = bitcast i32 0 to i32
%75 = bitcast i32 0 to i32
%76 = bitcast i32 0 to i32
%77 = bitcast i32 0 to i32
%78 = bitcast i32 0 to i32
%79 = bitcast i32 0 to i32
%80 = bitcast i32 0 to i32
%81 = bitcast i32 0 to i32
%82 = bitcast i32 0 to i32
%83 = bitcast i32 0 to i32
%84 = bitcast i32 0 to i32
%85 = bitcast i32 0 to i32
%86 = bitcast i32 0 to i32
%87 = bitcast i32 0 to i32
%88 = bitcast i32 0 to i32
%89 = bitcast i32 0 to i32
%90 = bitcast i32 0 to i32
%91 = bitcast i32 0 to i32
%92 = bitcast i32 0 to i32
%93 = bitcast i32 0 to i32
%94 = bitcast i32 0 to i32
%95 = bitcast i32 0 to i32
%96 = bitcast i32 0 to i32
%97 = bitcast i32 0 to i32
%98 = bitcast i32 0 to i32
; CHECK: store i32 -1, i32* @x, align 4
store i32 -1, i32* @x, align 4
ret i32 0
}
; Function Attrs: nounwind readnone
Move the complex address expression out of DIVariable and into an extra argument of the llvm.dbg.declare/llvm.dbg.value intrinsics. Previously, DIVariable was a variable-length field that has an optional reference to a Metadata array consisting of a variable number of complex address expressions. In the case of OpPiece expressions this is wasting a lot of storage in IR, because when an aggregate type is, e.g., SROA'd into all of its n individual members, the IR will contain n copies of the DIVariable, all alike, only differing in the complex address reference at the end. By making the complex address into an extra argument of the dbg.value/dbg.declare intrinsics, all of the pieces can reference the same variable and the complex address expressions can be uniqued across the CU, too. Down the road, this will allow us to move other flags, such as "indirection" out of the DIVariable, too. The new intrinsics look like this: declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr) declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr) This patch adds a new LLVM-local tag to DIExpressions, so we can detect and pretty-print DIExpression metadata nodes. What this patch doesn't do: This patch does not touch the "Indirect" field in DIVariable; but moving that into the expression would be a natural next step. http://reviews.llvm.org/D4919 rdar://problem/17994491 Thanks to dblaikie and dexonsmith for reviewing this patch! Note: I accidentally committed a bogus older version of this patch previously. llvm-svn: 218787
2014-10-02 02:55:02 +08:00
declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
Fixing a heisenbug where the memory dependence analysis behaves differently with and without -g. Adding a test case to make sure that the threshold used in the memory dependence analysis is respected. The test case also checks that debug intrinsics are not counted towards this threshold. Differential Revision: http://llvm-reviews.chandlerc.com/D2141 llvm-svn: 194646
2013-11-14 09:10:52 +08:00
!llvm.dbg.cu = !{!0}
Debug Info: update testing cases to specify the debug info version number. We are going to drop debug info without a version number or with a different version number, to make sure we don't crash when we see bitcode files with different debug info metadata format. llvm-svn: 195504
2013-11-23 05:49:45 +08:00
!llvm.module.flags = !{!11, !13}
Fixing a heisenbug where the memory dependence analysis behaves differently with and without -g. Adding a test case to make sure that the threshold used in the memory dependence analysis is respected. The test case also checks that debug intrinsics are not counted towards this threshold. Differential Revision: http://llvm-reviews.chandlerc.com/D2141 llvm-svn: 194646
2013-11-14 09:10:52 +08:00
Revert "DI: Fold constant arguments into a single MDString" This reverts commit r218914 while I investigate some bots. llvm-svn: 218918
2014-10-03 06:15:31 +08:00
!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.4", i1 true, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !9, metadata !2, metadata !""} ; [ DW_TAG_compile_unit ] [/home/tmp/test.c] [DW_LANG_C99]
Fixing a heisenbug where the memory dependence analysis behaves differently with and without -g. Adding a test case to make sure that the threshold used in the memory dependence analysis is respected. The test case also checks that debug intrinsics are not counted towards this threshold. Differential Revision: http://llvm-reviews.chandlerc.com/D2141 llvm-svn: 194646
2013-11-14 09:10:52 +08:00
!1 = metadata !{metadata !"test.c", metadata !"/home/tmp"}
!2 = metadata !{i32 0}
!3 = metadata !{metadata !4}
Revert "DI: Fold constant arguments into a single MDString" This reverts commit r218914 while I investigate some bots. llvm-svn: 218918
2014-10-03 06:15:31 +08:00
!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"test_within_limit", metadata !"test_within_limit", metadata !"", i32 3, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 ()* @test_within_limit, null, null, metadata !2, i32 4} ; [ DW_TAG_subprogram ] [line 3] [def] [scope 4] [test]
!5 = metadata !{i32 786473, metadata !1} ; [ DW_TAG_file_type ] [/home/tmp/test.c]
!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !7, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
Fixing a heisenbug where the memory dependence analysis behaves differently with and without -g. Adding a test case to make sure that the threshold used in the memory dependence analysis is respected. The test case also checks that debug intrinsics are not counted towards this threshold. Differential Revision: http://llvm-reviews.chandlerc.com/D2141 llvm-svn: 194646
2013-11-14 09:10:52 +08:00
!7 = metadata !{metadata !8}
Revert "DI: Fold constant arguments into a single MDString" This reverts commit r218914 while I investigate some bots. llvm-svn: 218918
2014-10-03 06:15:31 +08:00
!8 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
Fixing a heisenbug where the memory dependence analysis behaves differently with and without -g. Adding a test case to make sure that the threshold used in the memory dependence analysis is respected. The test case also checks that debug intrinsics are not counted towards this threshold. Differential Revision: http://llvm-reviews.chandlerc.com/D2141 llvm-svn: 194646
2013-11-14 09:10:52 +08:00
!9 = metadata !{metadata !10}
Revert "DI: Fold constant arguments into a single MDString" This reverts commit r218914 while I investigate some bots. llvm-svn: 218918
2014-10-03 06:15:31 +08:00
!10 = metadata !{i32 786484, i32 0, null, metadata !"x", metadata !"x", metadata !"", metadata !5, i32 1, metadata !8, i32 0, i32 1, i32* @x, null} ; [ DW_TAG_variable ] [x] [line 1] [def]
Fixing a heisenbug where the memory dependence analysis behaves differently with and without -g. Adding a test case to make sure that the threshold used in the memory dependence analysis is respected. The test case also checks that debug intrinsics are not counted towards this threshold. Differential Revision: http://llvm-reviews.chandlerc.com/D2141 llvm-svn: 194646
2013-11-14 09:10:52 +08:00
!11 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
!12 = metadata !{i32* undef}
Revert "DI: Fold constant arguments into a single MDString" This reverts commit r218914 while I investigate some bots. llvm-svn: 218918
2014-10-03 06:15:31 +08:00
!13 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}