test/Transforms/InstCombine/2011-09-03-Trampoline.ll

; RUN: opt -instcombine -S < %s | FileCheck %s

declare void @llvm.init.trampoline(i8*, i8*, i8*)
declare i8* @llvm.adjust.trampoline(i8*)
declare i32 @f(i8 * nest, i32)

; Most common case
define i32 @test0(i32 %n) !dbg !4 {
  %alloca = alloca [10 x i8], align 16
  %gep = getelementptr [10 x i8], [10 x i8]* %alloca, i32 0, i32 0
  call void @llvm.init.trampoline(i8* %gep, i8* bitcast (i32 (i8*, i32)* @f to i8*),
                                  i8* null)
  %tramp = call i8* @llvm.adjust.trampoline(i8* %gep)
  %function = bitcast i8* %tramp to i32(i32)*
  %ret = call i32 %function(i32 %n), !dbg !10
  ret i32 %ret

; CHECK: define i32 @test0(i32 %n) !dbg !4 {
; CHECK: %ret = call i32 @f(i8* nest null, i32 %n), !dbg !10
}

define i32 @test1(i32 %n, i8* %trampmem) {
  call void @llvm.init.trampoline(i8* %trampmem,
                                  i8* bitcast (i32 (i8*, i32)* @f to i8*),
                                  i8* null)
  %tramp = call i8* @llvm.adjust.trampoline(i8* %trampmem)
  %function = bitcast i8* %tramp to i32(i32)*
  %ret = call i32 %function(i32 %n)
  ret i32 %ret
; CHECK: define i32 @test1(i32 %n, i8* %trampmem) {
; CHECK: %ret = call i32 @f(i8* nest null, i32 %n)
}

define i32 @test2(i32 %n, i8* %trampmem) {
  %tramp = call i8* @llvm.adjust.trampoline(i8* %trampmem)
  %functiona = bitcast i8* %tramp to i32(i32)*
  %ret = call i32 %functiona(i32 %n)
  ret i32 %ret
; CHECK: define i32 @test2(i32 %n, i8* %trampmem) {
; CHECK: %ret = call i32 %functiona(i32 %n)
}

define i32 @test3(i32 %n, i8* %trampmem) {
  call void @llvm.init.trampoline(i8* %trampmem,
                                  i8* bitcast (i32 (i8*, i32)* @f to i8*),
                                  i8* null)

; CHECK: define i32 @test3(i32 %n, i8* %trampmem) {
; CHECK: %ret0 = call i32 @f(i8* nest null, i32 %n)
  %tramp0 = call i8* @llvm.adjust.trampoline(i8* %trampmem)
  %function0 = bitcast i8* %tramp0 to i32(i32)*
  %ret0 = call i32 %function0(i32 %n)

  ;; Not optimized since previous call could be writing.
  %tramp1 = call i8* @llvm.adjust.trampoline(i8* %trampmem)
  %function1 = bitcast i8* %tramp1 to i32(i32)*
  %ret1 = call i32 %function1(i32 %n)
; CHECK: %ret1 = call i32 %function1(i32 %n)

  ret i32 %ret1
}

define i32 @test4(i32 %n) {
  %alloca = alloca [10 x i8], align 16
  %gep = getelementptr [10 x i8], [10 x i8]* %alloca, i32 0, i32 0
  call void @llvm.init.trampoline(i8* %gep, i8* bitcast (i32 (i8*, i32)* @f to i8*),
                                  i8* null)

  %tramp0 = call i8* @llvm.adjust.trampoline(i8* %gep)
  %function0 = bitcast i8* %tramp0 to i32(i32)*
  %ret0 = call i32 %function0(i32 %n)

  %tramp1 = call i8* @llvm.adjust.trampoline(i8* %gep)
  %function1 = bitcast i8* %tramp0 to i32(i32)*
  %ret1 = call i32 %function1(i32 %n)

  %tramp2 = call i8* @llvm.adjust.trampoline(i8* %gep)
  %function2 = bitcast i8* %tramp2 to i32(i32)*
  %ret2 = call i32 %function2(i32 %n)

  ret i32 %ret2

; CHECK: define i32 @test4(i32 %n) {
; CHECK: %ret0 = call i32 @f(i8* nest null, i32 %n)
; CHECK: %ret1 = call i32 @f(i8* nest null, i32 %n)
; CHECK: %ret2 = call i32 @f(i8* nest null, i32 %n)
}

!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3}

!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.0 (trunk 127710)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2)
!1 = !DIFile(filename: "string.h", directory: "Game")
!2 = !{}
!3 = !{i32 1, !"Debug Info Version", i32 3}
!4 = distinct !DISubprogram(name: "passthru", scope: !1, file: !1, line: 79, type: !5, isLocal: true, isDefinition: true, scopeLine: 79, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !8)
!5 = !DISubroutineType(types: !6)
!6 = !{!7}
!7 = !DIDerivedType(tag: DW_TAG_pointer_type, scope: !0, baseType: null, size: 64, align: 64)
!8 = !{!9}
!9 = !DILocalVariable(name: "a", arg: 1, scope: !4, file: !1, line: 78, type: !7)
!10 = !DILocation(line: 78, column: 28, scope: !4)