forked from OSchip/llvm-project
91 lines
3.8 KiB
LLVM
91 lines
3.8 KiB
LLVM
; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/discriminator.prof | opt -analyze -branch-prob | FileCheck %s
|
|
; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/discriminator.prof | opt -analyze -branch-prob | FileCheck %s
|
|
|
|
; Original code
|
|
;
|
|
; 1 int foo(int i) {
|
|
; 2 int x = 0;
|
|
; 3 while (i < 100) {
|
|
; 4 if (i < 5) x--;
|
|
; 5 i++;
|
|
; 6 }
|
|
; 7 return x;
|
|
; 8 }
|
|
;
|
|
; In this test, if the loop is executed 100 times, the decrement operation
|
|
; at line 4 should only execute 5 times. This is reflected in the profile
|
|
; data for line offset 3. In Inputs/discriminator.prof, we have:
|
|
;
|
|
; 3: 100
|
|
; 3.1: 5
|
|
;
|
|
; This means that the predicate 'i < 5' (line 3) is executed 100 times,
|
|
; but the then branch (line 3.1) is only executed 5 times.
|
|
|
|
define i32 @foo(i32 %i) #0 !dbg !4 {
|
|
; CHECK: Printing analysis 'Branch Probability Analysis' for function 'foo':
|
|
entry:
|
|
%i.addr = alloca i32, align 4
|
|
%x = alloca i32, align 4
|
|
store i32 %i, i32* %i.addr, align 4
|
|
store i32 0, i32* %x, align 4, !dbg !10
|
|
br label %while.cond, !dbg !11
|
|
|
|
while.cond: ; preds = %if.end, %entry
|
|
%0 = load i32, i32* %i.addr, align 4, !dbg !12
|
|
%cmp = icmp slt i32 %0, 100, !dbg !12
|
|
br i1 %cmp, label %while.body, label %while.end, !dbg !12
|
|
; CHECK: edge while.cond -> while.body probability is 0x7d83ba68 / 0x80000000 = 98.06% [HOT edge]
|
|
; CHECK: edge while.cond -> while.end probability is 0x027c4598 / 0x80000000 = 1.94%
|
|
|
|
while.body: ; preds = %while.cond
|
|
%1 = load i32, i32* %i.addr, align 4, !dbg !14
|
|
%cmp1 = icmp slt i32 %1, 50, !dbg !14
|
|
br i1 %cmp1, label %if.then, label %if.end, !dbg !14
|
|
; CHECK: edge while.body -> if.then probability is 0x07878788 / 0x80000000 = 5.88%
|
|
; CHECK: edge while.body -> if.end probability is 0x78787878 / 0x80000000 = 94.12% [HOT edge]
|
|
|
|
if.then: ; preds = %while.body
|
|
%2 = load i32, i32* %x, align 4, !dbg !17
|
|
%dec = add nsw i32 %2, -1, !dbg !17
|
|
store i32 %dec, i32* %x, align 4, !dbg !17
|
|
br label %if.end, !dbg !17
|
|
|
|
if.end: ; preds = %if.then, %while.body
|
|
%3 = load i32, i32* %i.addr, align 4, !dbg !19
|
|
%inc = add nsw i32 %3, 1, !dbg !19
|
|
store i32 %inc, i32* %i.addr, align 4, !dbg !19
|
|
br label %while.cond, !dbg !20
|
|
|
|
while.end: ; preds = %while.cond
|
|
%4 = load i32, i32* %x, align 4, !dbg !21
|
|
ret i32 %4, !dbg !21
|
|
}
|
|
|
|
|
|
!llvm.dbg.cu = !{!0}
|
|
!llvm.module.flags = !{!7, !8}
|
|
!llvm.ident = !{!9}
|
|
|
|
!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.5 ", isOptimized: false, emissionKind: NoDebug, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
|
|
!1 = !DIFile(filename: "discriminator.c", directory: ".")
|
|
!2 = !{}
|
|
!4 = distinct !DISubprogram(name: "foo", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !0, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
|
|
!5 = !DIFile(filename: "discriminator.c", directory: ".")
|
|
!6 = !DISubroutineType(types: !2)
|
|
!7 = !{i32 2, !"Dwarf Version", i32 4}
|
|
!8 = !{i32 1, !"Debug Info Version", i32 3}
|
|
!9 = !{!"clang version 3.5 "}
|
|
!10 = !DILocation(line: 2, scope: !4)
|
|
!11 = !DILocation(line: 3, scope: !4)
|
|
!12 = !DILocation(line: 3, scope: !13)
|
|
!13 = !DILexicalBlockFile(discriminator: 2, file: !1, scope: !4)
|
|
!14 = !DILocation(line: 4, scope: !15)
|
|
!15 = distinct !DILexicalBlock(line: 4, column: 0, file: !1, scope: !16)
|
|
!16 = distinct !DILexicalBlock(line: 3, column: 0, file: !1, scope: !4)
|
|
!17 = !DILocation(line: 4, scope: !18)
|
|
!18 = !DILexicalBlockFile(discriminator: 2, file: !1, scope: !15)
|
|
!19 = !DILocation(line: 5, scope: !16)
|
|
!20 = !DILocation(line: 6, scope: !16)
|
|
!21 = !DILocation(line: 7, scope: !4)
|