[llvm] r224118 - [MachineScheduler] Fix for PR21807: minor code difference building with/without -g.
Andrea Di Biagio
andrea.dibiagio at gmail.com
Fri Dec 12 05:36:14 PST 2014
Reverted at revision 224121 due to buildbot failures:
clang-native-aarch64: stage 1 checked 1 unexpected failures 100
expected failures 217 unsupported tests 19833 expected passes failed -
stdioLLVM::misched-code-difference-with-debug.ll
llvm-s390x-linux1: test llvm 1 unexpected failures 90 expected
failures 107 unsupported tests 11865 expected passes failed -
stdioLLVM::misched-code-difference-with-debug.ll
clang-cmake-armv7-a15-full: stage 1
On Fri, Dec 12, 2014 at 12:41 PM, Andrea Di Biagio
<Andrea_DiBiagio at sn.scee.net> wrote:
> Author: adibiagio
> Date: Fri Dec 12 06:41:22 2014
> New Revision: 224118
>
> URL: http://llvm.org/viewvc/llvm-project?rev=224118&view=rev
> Log:
> [MachineScheduler] Fix for PR21807: minor code difference building with/without -g.
>
> This patch fixes the issue reported as PR21807. There was a minor difference
> in the generated code depending on the -g flag.
>
> The cause was that with -g the machine scheduler used a different
> scheduling strategy. This decision was based on the number of instructions
> in a schedule region and included debug instructions in that count.
>
> This patch fixes the issue in MISched and provides a test.
>
> Patch by Russell Gallop!
>
> Added:
> llvm/trunk/test/CodeGen/X86/misched-code-difference-with-debug.ll
> Modified:
> llvm/trunk/lib/CodeGen/MachineScheduler.cpp
>
> Modified: llvm/trunk/lib/CodeGen/MachineScheduler.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineScheduler.cpp?rev=224118&r1=224117&r2=224118&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/MachineScheduler.cpp (original)
> +++ llvm/trunk/lib/CodeGen/MachineScheduler.cpp Fri Dec 12 06:41:22 2014
> @@ -430,9 +430,11 @@ void MachineSchedulerBase::scheduleRegio
> // instruction stream until we find the nearest boundary.
> unsigned NumRegionInstrs = 0;
> MachineBasicBlock::iterator I = RegionEnd;
> - for(;I != MBB->begin(); --I, --RemainingInstrs, ++NumRegionInstrs) {
> + for(;I != MBB->begin(); --I, --RemainingInstrs) {
> if (isSchedBoundary(std::prev(I), MBB, MF, TII, IsPostRA))
> break;
> + if (!I->isDebugValue())
> + ++NumRegionInstrs;
> }
> // Notify the scheduler of the region, even if we may skip scheduling
> // it. Perhaps it still needs to be bundled.
>
> Added: llvm/trunk/test/CodeGen/X86/misched-code-difference-with-debug.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/misched-code-difference-with-debug.ll?rev=224118&view=auto
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/misched-code-difference-with-debug.ll (added)
> +++ llvm/trunk/test/CodeGen/X86/misched-code-difference-with-debug.ll Fri Dec 12 06:41:22 2014
> @@ -0,0 +1,90 @@
> +; RUN: llc < %s -mcpu=generic | FileCheck %s
> +; Both functions should produce the same code. The presence of debug values
> +; should not affect the scheduling strategy.
> +; Generated from:
> +; char argc;
> +; class C {
> +; public:
> +; int test(char ,char ,char ,...);
> +; };
> +; void foo() {
> +; C c;
> +; char lc = argc;
> +; c.test(0,argc,0,lc);
> +; c.test(0,argc,0,lc);
> +; }
> +;
> +; with
> +; clang -O2 -c test.cpp -emit-llvm -S
> +; clang -O2 -c test.cpp -emit-llvm -S -g
> +;
> +
> +
> +%class.C = type { i8 }
> +
> + at argc = global i8 0, align 1
> +
> +declare i32 @test_function(%class.C*, i8 signext, i8 signext, i8 signext, ...)
> +
> +; CHECK-LABEL: test_without_debug
> +; CHECK: movl [[A:%[a-z]+]], [[B:%[a-z]+]]
> +; CHECK-NEXT: movl [[A]], [[C:%[a-z]+]]
> +define void @test_without_debug() {
> +entry:
> + %c = alloca %class.C, align 1
> + %0 = load i8* @argc, align 1
> + %conv = sext i8 %0 to i32
> + %call = call i32 (%class.C*, i8, i8, i8, ...)* @test_function(%class.C* %c, i8 signext 0, i8 signext %0, i8 signext 0, i32 %conv)
> + %1 = load i8* @argc, align 1
> + %call2 = call i32 (%class.C*, i8, i8, i8, ...)* @test_function(%class.C* %c, i8 signext 0, i8 signext %1, i8 signext 0, i32 %conv)
> + ret void
> +}
> +
> +; CHECK-LABEL: test_with_debug
> +; CHECK: movl [[A]], [[B]]
> +; CHECK-NEXT: movl [[A]], [[C]]
> +define void @test_with_debug() {
> +entry:
> + %c = alloca %class.C, align 1
> + %0 = load i8* @argc, align 1
> + tail call void @llvm.dbg.value(metadata !{i8 %0}, i64 0, metadata !19, metadata !29)
> + %conv = sext i8 %0 to i32
> + tail call void @llvm.dbg.value(metadata !{%class.C* %c}, i64 0, metadata !18, metadata !29)
> + %call = call i32 (%class.C*, i8, i8, i8, ...)* @test_function(%class.C* %c, i8 signext 0, i8 signext %0, i8 signext 0, i32 %conv)
> + %1 = load i8* @argc, align 1
> + call void @llvm.dbg.value(metadata !{%class.C* %c}, i64 0, metadata !18, metadata !29)
> + %call2 = call i32 (%class.C*, i8, i8, i8, ...)* @test_function(%class.C* %c, i8 signext 0, i8 signext %1, i8 signext 0, i32 %conv)
> + ret void
> +}
> +
> +declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
> +
> +!llvm.dbg.cu = !{!0}
> +!llvm.module.flags = !{!22, !23}
> +
> +!0 = metadata !{metadata !"", metadata !1, metadata !2, metadata !3, metadata !12, metadata !20, metadata !2} ; [ DW_TAG_compile_unit ] [test.cpp] [DW_LANG_C_plus_plus]
> +!1 = metadata !{metadata !"test.cpp", metadata !""}
> +!2 = metadata !{}
> +!3 = metadata !{metadata !4}
> +!4 = metadata !{metadata !"0x2\00C\002\008\008\000\000\000", metadata !1, null, null, metadata !5, null, null, metadata !"_ZTS1C"} ; [ DW_TAG_class_type ] [C] [line 2, size 8, align 8, offset 0] [def] [from ]
> +!5 = metadata !{metadata !6}
> +!6 = metadata !{metadata !"", metadata !1, metadata !"_ZTS1C", metadata !7, null, null, null, null, null} ; [ DW_TAG_subprogram ] [line 4] [public] [test]
> +!7 = metadata !{metadata !"", null, null, null, metadata !8, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
> +!8 = metadata !{metadata !9, metadata !10, metadata !11, metadata !11, metadata !11, null}
> +!9 = metadata !{metadata !"", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
> +!10 = metadata !{metadata !"", null, null, metadata !"_ZTS1C"} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [artificial] [from _ZTS1C]
> +!11 = metadata !{metadata !"0x24\00char\000\008\008\000\000\006", null, null} ; [ DW_TAG_base_type ] [char] [line 0, size 8, align 8, offset 0, enc DW_ATE_signed_char]
> +!12 = metadata !{metadata !13}
> +!13 = metadata !{metadata !"0x2e\00test_with_debug\00test_with_debug\00test_with_debug\006\000\001\000\000\00256\001\006", metadata !1, metadata !14, metadata !15, null, void ()* @test_with_debug, null, null, metadata !17} ; [ DW_TAG_subprogram ] [line 6] [def] [test_with_debug]
> +!14 = metadata !{metadata !"0x29", metadata !1}
> +!15 = metadata !{metadata !"0x15\00\000\000\000\000\000\000", null, null, null, metadata !16, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
> +!16 = metadata !{null}
> +!17 = metadata !{metadata !18, metadata !19}
> +!18 = metadata !{metadata !"0x100\00c\007\000", metadata !13, metadata !14, metadata !"_ZTS1C"} ; [ DW_TAG_auto_variable ] [c] [line 7]
> +!19 = metadata !{metadata !"0x100\00lc\008\000", metadata !13, metadata !14, metadata !11} ; [ DW_TAG_auto_variable ] [lc] [line 8]
> +!20 = metadata !{metadata !21}
> +!21 = metadata !{metadata !"0x34\00argc\00argc\00\001\000\001", null, metadata !14, metadata !11, i8* @argc, null} ; [ DW_TAG_variable ] [argc] [line 1] [def]
> +!22 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
> +!23 = metadata !{i32 2, metadata !"Debug Info Version", i32 2}
> +!25 = metadata !{i32 8, i32 3, metadata !13, null}
> +!29 = metadata !{metadata !"0x102"} ; [ DW_TAG_expression ]
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
More information about the llvm-commits
mailing list