[llvm] r285110 - revert: "Remove debug location from common tail when tail-merging"

Robert Lougher via llvm-commits llvm-commits at lists.llvm.org
Tue Oct 25 13:17:58 PDT 2016


Author: rlougher
Date: Tue Oct 25 15:17:58 2016
New Revision: 285110

URL: http://llvm.org/viewvc/llvm-project?rev=285110&view=rev
Log:
revert: "Remove debug location from common tail when tail-merging"

This reverts r285093, as it caused unexpected buildbot failures on
clang-ppc64le-linux, clang-ppc64be-linux, clang-ppc64be-linux-multistage
and clang-ppc64be-linux-lnt.  Failing test ubsan/TestCases/TypeCheck/vptr.cpp.


Removed:
    llvm/trunk/test/DebugInfo/X86/tail-merge.ll
Modified:
    llvm/trunk/lib/CodeGen/BranchFolding.cpp
    llvm/trunk/test/DebugInfo/COFF/local-variables.ll

Modified: llvm/trunk/lib/CodeGen/BranchFolding.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/BranchFolding.cpp?rev=285110&r1=285109&r2=285110&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/BranchFolding.cpp (original)
+++ llvm/trunk/lib/CodeGen/BranchFolding.cpp Tue Oct 25 15:17:58 2016
@@ -720,6 +720,8 @@ bool BranchFolder::CreateCommonTailOnlyB
     SameTails[commonTailIndex].getTailStartPos();
   MachineBasicBlock *MBB = SameTails[commonTailIndex].getBlock();
 
+  // If the common tail includes any debug info we will take it pretty
+  // randomly from one of the inputs.  Might be better to remove it?
   DEBUG(dbgs() << "\nSplitting BB#" << MBB->getNumber() << ", size "
                << maxCommonTailLength);
 
@@ -896,11 +898,6 @@ bool BranchFolder::TryTailMergeBlocks(Ma
     // Recompute common tail MBB's edge weights and block frequency.
     setCommonTailEdgeWeights(*MBB);
 
-    // Remove the original debug location from the common tail.
-    for (auto &MI : *MBB)
-      if (!MI.isDebugValue())
-        MI.setDebugLoc(DebugLoc());
-
     // MBB is common tail.  Adjust all other BB's to jump to this one.
     // Traversal must be forwards so erases work.
     DEBUG(dbgs() << "\nUsing common tail in BB#" << MBB->getNumber()

Modified: llvm/trunk/test/DebugInfo/COFF/local-variables.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/COFF/local-variables.ll?rev=285110&r1=285109&r2=285110&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/COFF/local-variables.ll (original)
+++ llvm/trunk/test/DebugInfo/COFF/local-variables.ll Tue Oct 25 15:17:58 2016
@@ -63,9 +63,11 @@
 ; ASM:         .cv_loc 2 1 5 3                 # t.cpp:5:3
 ; ASM:         callq   capture
 ; ASM:         leaq    36(%rsp), %rcx
-; ASM: [[else_end:\.Ltmp.*]]:
+; ASM: [[inline_site2_end:\.Ltmp.*]]:
 ; ASM: .LBB0_3:                                # %if.end
+; ASM:         .cv_loc 0 1 15 5                # t.cpp:15:5
 ; ASM:         callq   capture
+; ASM: [[else_end:\.Ltmp.*]]:
 ; ASM:         .cv_loc 0 1 17 1                # t.cpp:17:1
 ; ASM:         nop
 ; ASM:         addq    $56, %rsp
@@ -99,7 +101,7 @@
 ; ASM: .long   116                     # TypeIndex
 ; ASM: .short  0                       # Flags
 ; ASM: .asciz  "v"
-; ASM: .cv_def_range    [[inline_site2]] [[else_end]], "E\021O\001\000\0000\000\000\000"
+; ASM: .cv_def_range    [[inline_site2]] [[inline_site2_end]], "E\021O\001\000\0000\000\000\000"
 ; ASM: .short  4430                    # Record kind: S_INLINESITE_END
 
 ; OBJ:  Subsection [
@@ -157,7 +159,7 @@
 ; OBJ:      LocalVariableAddrRange {
 ; OBJ:        OffsetStart: .text+0x2D
 ; OBJ:        ISectStart: 0x0
-; OBJ:        Range: 0x1F
+; OBJ:        Range: 0x24
 ; OBJ:      }
 ; OBJ:    }
 ; OBJ:    InlineSite {
@@ -198,7 +200,7 @@
 ; OBJ:        ChangeLineOffset: 1
 ; OBJ:        ChangeCodeOffset: 0x35
 ; OBJ:        ChangeCodeOffsetAndLineOffset: {CodeOffset: 0xD, LineOffset: 1}
-; OBJ:        ChangeCodeLength: 0xF
+; OBJ:        ChangeCodeLength: 0xA
 ; OBJ:      ]
 ; OBJ:    }
 ; OBJ:    Local {

Removed: llvm/trunk/test/DebugInfo/X86/tail-merge.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/tail-merge.ll?rev=285109&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/tail-merge.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/tail-merge.ll (removed)
@@ -1,76 +0,0 @@
-; RUN: llc %s -mtriple=x86_64-unknown-unknown -use-unknown-locations=true -o - | FileCheck %s
-
-; Generated with "clang -gline-tables-only -c -emit-llvm -o - | opt -sroa -S"
-; from source:
-;
-; extern int foo(int);
-; extern int bar(int);
-;
-; int test(int a, int b) {
-;   if(b)
-;     a += foo(a);
-;   else
-;     a += bar(a);
-;   return a;
-; }
-
-; When tail-merging the debug location of the common tail should be removed.
-
-; CHECK-LABEL: test:
-; CHECK: movl	%edi, [[REG:%.*]]
-; CHECK: testl	%esi, %esi
-; CHECK: je	[[ELSE:.LBB[0-9]+_[0-9]+]]
-; CHECK: .loc	1 6 10
-; CHECK: callq	foo
-; CHECK: jmp	[[TAIL:.LBB[0-9]+_[0-9]+]]
-; CHECK: [[ELSE]]:
-; CHECK: .loc	1 8 10
-; CHECK: callq	bar
-; CHECK: [[TAIL]]:
-; CHECK: .loc	1 0 0
-; CHECK: addl	[[REG]], %eax
-; CHECK: .loc	1 9 3
-
-target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64-unknown-linux-gnu"
-
-define i32 @test(i32 %a, i32 %b) !dbg !6 {
-entry:
-  %tobool = icmp ne i32 %b, 0, !dbg !8
-  br i1 %tobool, label %if.then, label %if.else, !dbg !8
-
-if.then:                                          ; preds = %entry
-  %call = call i32 @foo(i32 %a), !dbg !9
-  %add = add nsw i32 %a, %call, !dbg !10
-  br label %if.end, !dbg !11
-
-if.else:                                          ; preds = %entry
-  %call1 = call i32 @bar(i32 %a), !dbg !12
-  %add2 = add nsw i32 %a, %call1, !dbg !13
-  br label %if.end
-
-if.end:                                           ; preds = %if.else, %if.then
-  %a.addr.0 = phi i32 [ %add, %if.then ], [ %add2, %if.else ]
-  ret i32 %a.addr.0, !dbg !14
-}
-
-declare i32 @foo(i32)
-declare i32 @bar(i32)
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!3, !4}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "", isOptimized: false, runtimeVersion: 0, emissionKind: LineTablesOnly, enums: !2)
-!1 = !DIFile(filename: "test.c", directory: "")
-!2 = !{}
-!3 = !{i32 2, !"Dwarf Version", i32 4}
-!4 = !{i32 2, !"Debug Info Version", i32 3}
-!6 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !7, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
-!7 = !DISubroutineType(types: !2)
-!8 = !DILocation(line: 5, column: 6, scope: !6)
-!9 = !DILocation(line: 6, column: 10, scope: !6)
-!10 = !DILocation(line: 6, column: 7, scope: !6)
-!11 = !DILocation(line: 6, column: 5, scope: !6)
-!12 = !DILocation(line: 8, column: 10, scope: !6)
-!13 = !DILocation(line: 8, column: 7, scope: !6)
-!14 = !DILocation(line: 9, column: 3, scope: !6)




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