simplifycfg_sink_last_inst.ll 3.96 KB
; RUN: opt -simplifycfg -sink-common-insts -S < %s | FileCheck %s

target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

; Simplify CFG will try to sink the last instruction in a series of basic
; blocks, creating a "common" instruction in the successor block.  If the
; debug locations of the commoned instructions have different file/line
; numbers the debug location of the common instruction should be a merged
; location.

; Generated from source:

; extern int foo(void);
; extern int bar(void);
; 
; int test(int a, int b) {
;   if(a)
;     b -= foo();
;   else
;     b -= bar();
;   return b;
; }

; CHECK: define i32 @test
; CHECK-LABEL: if.end:
; CHECK: %[[PHI:.*]] = phi i32 [ %call1, %if.else ], [ %call, %if.then ]
; CHECK: sub nsw i32 %b, %[[PHI]], !dbg [[testMergedLoc:![0-9]+]]
; CHECK: ret i32

define i32 @test(i32 %a, i32 %b) !dbg !6 {
entry:
  %tobool = icmp ne i32 %a, 0, !dbg !8
  br i1 %tobool, label %if.then, label %if.else, !dbg !8

if.then:                                          ; preds = %entry
  %call = call i32 @foo(), !dbg !9
  %sub = sub nsw i32 %b, %call, !dbg !10
  br label %if.end, !dbg !11

if.else:                                          ; preds = %entry
  %call1 = call i32 @bar(), !dbg !12
  %sub2 = sub nsw i32 %b, %call1, !dbg !13
  br label %if.end

if.end:                                           ; preds = %if.else, %if.then
  %b.addr.0 = phi i32 [ %sub, %if.then ], [ %sub2, %if.else ]
  ret i32 %b.addr.0, !dbg !14
}

; When the commoned instructions have the same debug location, this location
; should be used as the location of the common instruction.

; Generated from source (with -mllvm -no-discriminators and -gno-column-info):

; int test2(int a, int b) {
;   if(a) b -= foo(); else b -= bar();
;   return b;
; }

; CHECK: define i32 @test2
; CHECK-LABEL: if.end:
; CHECK: %[[PHI:.*]] = phi i32 [ %call1, %if.else ], [ %call, %if.then ]
; CHECK: sub nsw i32 %b, %[[PHI]], !dbg [[test2Loc:![0-9]+]]
; CHECK: ret i32

define i32 @test2(i32 %a, i32 %b) !dbg !15 {
entry:
  %tobool = icmp ne i32 %a, 0, !dbg !16
  br i1 %tobool, label %if.then, label %if.else, !dbg !16

if.then:                                          ; preds = %entry
  %call = call i32 @foo(), !dbg !16
  %sub = sub nsw i32 %b, %call, !dbg !16
  br label %if.end, !dbg !16

if.else:                                          ; preds = %entry
  %call1 = call i32 @bar(), !dbg !16
  %sub2 = sub nsw i32 %b, %call1, !dbg !16
  br label %if.end

if.end:                                           ; preds = %if.else, %if.then
  %b.addr.0 = phi i32 [ %sub, %if.then ], [ %sub2, %if.else ]
  ret i32 %b.addr.0, !dbg !17
}

; CHECK: [[testMergedLoc]] = !DILocation(line: 0
; CHECK: [[test2Loc]] = !DILocation(line: 17

declare i32 @foo()
declare i32 @bar()

!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: 8, type: !7, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
!7 = !DISubroutineType(types: !2)
!8 = !DILocation(line: 9, column: 6, scope: !6)
!9 = !DILocation(line: 10, column: 10, scope: !6)
!10 = !DILocation(line: 10, column: 7, scope: !6)
!11 = !DILocation(line: 10, column: 5, scope: !6)
!12 = !DILocation(line: 12, column: 10, scope: !6)
!13 = !DILocation(line: 12, column: 7, scope: !6)
!14 = !DILocation(line: 13, column: 3, scope: !6)
!15 = distinct !DISubprogram(name: "test2", scope: !1, file: !1, line: 16, type: !7, isLocal: false, isDefinition: true, scopeLine: 16, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
!16 = !DILocation(line: 17, scope: !15)
!17 = !DILocation(line: 18, scope: !15)