malloc-free-delete.ll 14.5 KB
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
; PR1201
define i32 @main(i32 %argc, i8** %argv) {
; CHECK-LABEL: @main(
; CHECK-NEXT:    ret i32 0
;
  %c_19 = alloca i8*
  %malloc_206 = tail call i8* @malloc(i32 mul (i32 ptrtoint (i8* getelementptr (i8, i8* null, i32 1) to i32), i32 10))
  store i8* %malloc_206, i8** %c_19
  %tmp_207 = load i8*, i8** %c_19
  tail call void @free(i8* %tmp_207)
  ret i32 0
}

define i32 @dead_aligned_alloc(i32 %size, i32 %alignment, i8 %value) {
; CHECK-LABEL: @dead_aligned_alloc(
; CHECK-NEXT:    ret i32 0
;
  %aligned_allocation = tail call i8* @aligned_alloc(i32 %alignment, i32 %size)
  store i8 %value, i8* %aligned_allocation
  tail call void @free(i8* %aligned_allocation)
  ret i32 0
}

declare noalias i8* @calloc(i32, i32) nounwind
declare noalias i8* @malloc(i32)
declare noalias i8* @aligned_alloc(i32, i32)
declare void @free(i8*)

define i1 @foo() {
; CHECK-LABEL: @foo(
; CHECK-NEXT:    ret i1 false
;
  %m = call i8* @malloc(i32 1)
  %z = icmp eq i8* %m, null
  call void @free(i8* %m)
  ret i1 %z
}

declare void @llvm.lifetime.start.p0i8(i64, i8*)
declare void @llvm.lifetime.end.p0i8(i64, i8*)
declare i64 @llvm.objectsize.i64(i8*, i1)
declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i1) nounwind
declare void @llvm.memmove.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i1) nounwind
declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i1) nounwind

define void @test3(i8* %src) {
; CHECK-LABEL: @test3(
; CHECK-NEXT:    ret void
;
  %a = call noalias i8* @malloc(i32 10)
  call void @llvm.lifetime.start.p0i8(i64 10, i8* %a)
  call void @llvm.lifetime.end.p0i8(i64 10, i8* %a)
  %size = call i64 @llvm.objectsize.i64(i8* %a, i1 true)
  store i8 42, i8* %a
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %a, i8* %src, i32 32, i1 false)
  call void @llvm.memmove.p0i8.p0i8.i32(i8* %a, i8* %src, i32 32, i1 false)
  call void @llvm.memset.p0i8.i32(i8* %a, i8 5, i32 32, i1 false)
  %alloc2 = call noalias i8* @calloc(i32 5, i32 7) nounwind
  %z = icmp ne i8* %alloc2, null
  ret void
}

;; This used to crash.
define void @test4() {
; CHECK-LABEL: @test4(
; CHECK-NEXT:    ret void
;
  %A = call i8* @malloc(i32 16000)
  %B = bitcast i8* %A to double*
  %C = bitcast double* %B to i8*
  call void @free(i8* %C)
  ret void
}

define void @test5(i8* %ptr, i8** %esc) {
; CHECK-LABEL: @test5(
; CHECK-NEXT:    [[A:%.*]] = call dereferenceable_or_null(700) i8* @malloc(i32 700)
; CHECK-NEXT:    [[B:%.*]] = call dereferenceable_or_null(700) i8* @malloc(i32 700)
; CHECK-NEXT:    [[C:%.*]] = call dereferenceable_or_null(700) i8* @malloc(i32 700)
; CHECK-NEXT:    [[D:%.*]] = call dereferenceable_or_null(700) i8* @malloc(i32 700)
; CHECK-NEXT:    [[E:%.*]] = call dereferenceable_or_null(700) i8* @malloc(i32 700)
; CHECK-NEXT:    [[F:%.*]] = call dereferenceable_or_null(700) i8* @malloc(i32 700)
; CHECK-NEXT:    [[G:%.*]] = call dereferenceable_or_null(700) i8* @malloc(i32 700)
; CHECK-NEXT:    call void @llvm.memcpy.p0i8.p0i8.i32(i8* nonnull align 1 dereferenceable(32) [[PTR:%.*]], i8* nonnull align 1 dereferenceable(32) [[A]], i32 32, i1 false)
; CHECK-NEXT:    call void @llvm.memmove.p0i8.p0i8.i32(i8* nonnull align 1 dereferenceable(32) [[PTR]], i8* nonnull align 1 dereferenceable(32) [[B]], i32 32, i1 false)
; CHECK-NEXT:    store i8* [[C]], i8** [[ESC:%.*]], align 8
; CHECK-NEXT:    call void @llvm.memcpy.p0i8.p0i8.i32(i8* [[D]], i8* [[PTR]], i32 32, i1 true)
; CHECK-NEXT:    call void @llvm.memmove.p0i8.p0i8.i32(i8* [[E]], i8* [[PTR]], i32 32, i1 true)
; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* [[F]], i8 5, i32 32, i1 true)
; CHECK-NEXT:    store volatile i8 4, i8* [[G]], align 1
; CHECK-NEXT:    ret void
;
  %a = call i8* @malloc(i32 700)
  %b = call i8* @malloc(i32 700)
  %c = call i8* @malloc(i32 700)
  %d = call i8* @malloc(i32 700)
  %e = call i8* @malloc(i32 700)
  %f = call i8* @malloc(i32 700)
  %g = call i8* @malloc(i32 700)
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %ptr, i8* %a, i32 32, i1 false)
  call void @llvm.memmove.p0i8.p0i8.i32(i8* %ptr, i8* %b, i32 32, i1 false)
  store i8* %c, i8** %esc
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %d, i8* %ptr, i32 32, i1 true)
  call void @llvm.memmove.p0i8.p0i8.i32(i8* %e, i8* %ptr, i32 32, i1 true)
  call void @llvm.memset.p0i8.i32(i8* %f, i8 5, i32 32, i1 true)
  store volatile i8 4, i8* %g
  ret void
}

;; When a basic block contains only a call to free and this block is accessed
;; through a test of the argument of free against null, move the call in the
;; predecessor block.
;; Using simplifycfg will remove the empty basic block and the branch operation
;; Then, performing a dead elimination will remove the comparison.
;; This is what happens with -O1 and upper.
define void @test6(i8* %foo) minsize {
; CHECK-LABEL: @test6(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq i8* [[FOO:%.*]], null
; CHECK-NEXT:    tail call void @free(i8* [[FOO]])
; CHECK-NEXT:    br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]]
; CHECK:       if.then:
; CHECK-NEXT:    br label [[IF_END]]
; CHECK:       if.end:
; CHECK-NEXT:    ret void
;
;; Call to free moved
;; Block is now empty and may be simplified by simplifycfg
entry:
  %tobool = icmp eq i8* %foo, null
  br i1 %tobool, label %if.end, label %if.then

if.then:                                          ; preds = %entry
  tail call void @free(i8* %foo)
  br label %if.end

if.end:                                           ; preds = %entry, %if.then
  ret void
}

; Same optimization with even a builtin 'operator delete' would be
; incorrect in general.
; 'if (p) delete p;' cannot result in a call to 'operator delete(0)'.
define void @test6a(i8* %foo) minsize {
; CHECK-LABEL: @test6a(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq i8* [[FOO:%.*]], null
; CHECK-NEXT:    br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]]
; CHECK:       if.then:
; CHECK-NEXT:    tail call void @_ZdlPv(i8* [[FOO]])
; CHECK-NEXT:    br label [[IF_END]]
; CHECK:       if.end:
; CHECK-NEXT:    ret void
entry:
  %tobool = icmp eq i8* %foo, null
  br i1 %tobool, label %if.end, label %if.then

if.then:                                          ; preds = %entry
  tail call void @_ZdlPv(i8* %foo) builtin
  br label %if.end

if.end:                                           ; preds = %entry, %if.then
  ret void
}

declare i8* @_ZnwmRKSt9nothrow_t(i64, i8*) nobuiltin
declare void @_ZdlPvRKSt9nothrow_t(i8*, i8*) nobuiltin
declare i32 @__gxx_personality_v0(...)
declare void @_ZN1AC2Ev(i8* %this)

define void @test7() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
; CHECK-LABEL: @test7(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    invoke void @_ZN1AC2Ev(i8* undef)
; CHECK-NEXT:    to label [[DOTNOEXC_I:%.*]] unwind label [[LPAD_I:%.*]]
; CHECK:       .noexc.i:
; CHECK-NEXT:    unreachable
; CHECK:       lpad.i:
; CHECK-NEXT:    [[TMP0:%.*]] = landingpad { i8*, i32 }
; CHECK-NEXT:    cleanup
; CHECK-NEXT:    resume { i8*, i32 } [[TMP0]]
;
entry:
  %nt = alloca i8
  %call.i = tail call i8* @_ZnwmRKSt9nothrow_t(i64 1, i8* %nt) builtin nounwind
  invoke void @_ZN1AC2Ev(i8* undef)
  to label %.noexc.i unwind label %lpad.i

.noexc.i:                                         ; preds = %entry
  unreachable

lpad.i:                                           ; preds = %entry
  %0 = landingpad { i8*, i32 } cleanup
  call void @_ZdlPvRKSt9nothrow_t(i8* %call.i, i8* %nt) builtin nounwind
  resume { i8*, i32 } %0
}

declare i8* @_Znwm(i64) nobuiltin
define i8* @_Znwj(i32 %n) nobuiltin {
; CHECK-LABEL: @_Znwj(
; CHECK-NEXT:    [[Z:%.*]] = zext i32 [[N:%.*]] to i64
; CHECK-NEXT:    [[M:%.*]] = call i8* @_Znwm(i64 [[Z]])
; CHECK-NEXT:    ret i8* [[M]]
;
  %z = zext i32 %n to i64
  %m = call i8* @_Znwm(i64 %z)
  ret i8* %m
}
declare i8* @_Znam(i64) nobuiltin
declare i8* @_Znaj(i32) nobuiltin
declare void @_ZdlPv(i8*) nobuiltin
declare void @_ZdaPv(i8*) nobuiltin

define linkonce void @_ZdlPvm(i8* %p, i64) nobuiltin {
; CHECK-LABEL: @_ZdlPvm(
; CHECK-NEXT:    call void @_ZdlPv(i8* [[P:%.*]])
; CHECK-NEXT:    ret void
;
  call void @_ZdlPv(i8* %p)
  ret void
}
define linkonce void @_ZdlPvj(i8* %p, i32) nobuiltin {
; CHECK-LABEL: @_ZdlPvj(
; CHECK-NEXT:    call void @_ZdlPv(i8* [[P:%.*]])
; CHECK-NEXT:    ret void
;
  call void @_ZdlPv(i8* %p)
  ret void
}
define linkonce void @_ZdaPvm(i8* %p, i64) nobuiltin {
; CHECK-LABEL: @_ZdaPvm(
; CHECK-NEXT:    call void @_ZdaPv(i8* [[P:%.*]])
; CHECK-NEXT:    ret void
;
  call void @_ZdaPv(i8* %p)
  ret void
}
define linkonce void @_ZdaPvj(i8* %p, i32) nobuiltin {
; CHECK-LABEL: @_ZdaPvj(
; CHECK-NEXT:    call void @_ZdaPv(i8* [[P:%.*]])
; CHECK-NEXT:    ret void
;
  call void @_ZdaPv(i8* %p)
  ret void
}


; new(size_t, align_val_t)
declare i8* @_ZnwmSt11align_val_t(i64, i64) nobuiltin
declare i8* @_ZnwjSt11align_val_t(i32, i32) nobuiltin
; new[](size_t, align_val_t)
declare i8* @_ZnamSt11align_val_t(i64, i64) nobuiltin
declare i8* @_ZnajSt11align_val_t(i32, i32) nobuiltin
; new(size_t, align_val_t, nothrow)
declare i8* @_ZnwmSt11align_val_tRKSt9nothrow_t(i64, i64, i8*) nobuiltin
declare i8* @_ZnwjSt11align_val_tRKSt9nothrow_t(i32, i32, i8*) nobuiltin
; new[](size_t, align_val_t, nothrow)
declare i8* @_ZnamSt11align_val_tRKSt9nothrow_t(i64, i64, i8*) nobuiltin
declare i8* @_ZnajSt11align_val_tRKSt9nothrow_t(i32, i32, i8*) nobuiltin
; delete(void*, align_val_t)
declare void @_ZdlPvSt11align_val_t(i8*, i64) nobuiltin
; delete[](void*, align_val_t)
declare void @_ZdaPvSt11align_val_t(i8*, i64) nobuiltin
; delete(void*, align_val_t, nothrow)
declare void @_ZdlPvSt11align_val_tRKSt9nothrow_t(i8*, i64, i8*) nobuiltin
; delete[](void*, align_val_t, nothrow)
declare void @_ZdaPvSt11align_val_tRKSt9nothrow_t(i8*, i64, i8*) nobuiltin
; delete(void*, unsigned int, align_val_t)
declare void @_ZdlPvjSt11align_val_t(i8*, i32, i32) nobuiltin
; delete(void*, unsigned long, align_val_t)
declare void @_ZdlPvmSt11align_val_t(i8*, i64, i64) nobuiltin
; delete[](void*, unsigned int, align_val_t)
declare void @_ZdaPvjSt11align_val_t(i8*, i32, i32) nobuiltin
; delete[](void*, unsigned long, align_val_t)
declare void @_ZdaPvmSt11align_val_t(i8*, i64, i64) nobuiltin

declare void @llvm.assume(i1)

define void @test8() {
; CHECK-LABEL: @test8(
; CHECK-NEXT:    ret void
;
  %nt = alloca i8
  %nw = call i8* @_Znwm(i64 32) builtin
  call void @_ZdlPv(i8* %nw) builtin
  %na = call i8* @_Znam(i64 32) builtin
  call void @_ZdaPv(i8* %na) builtin
  %nwm = call i8* @_Znwm(i64 32) builtin
  call void @_ZdlPvm(i8* %nwm, i64 32) builtin
  %nwj = call i8* @_Znwj(i32 32) builtin
  call void @_ZdlPvj(i8* %nwj, i32 32) builtin
  %nam = call i8* @_Znam(i64 32) builtin
  call void @_ZdaPvm(i8* %nam, i64 32) builtin
  %naj = call i8* @_Znaj(i32 32) builtin
  call void @_ZdaPvj(i8* %naj, i32 32) builtin
  %nwa = call i8* @_ZnwmSt11align_val_t(i64 32, i64 8) builtin
  call void @_ZdlPvSt11align_val_t(i8* %nwa, i64 8) builtin
  %naa = call i8* @_ZnamSt11align_val_t(i64 32, i64 8) builtin
  call void @_ZdaPvSt11align_val_t(i8* %naa, i64 8) builtin
  %nwja = call i8* @_ZnwjSt11align_val_t(i32 32, i32 8) builtin
  call void @_ZdlPvSt11align_val_t(i8* %nwja, i64 8) builtin
  %naja = call i8* @_ZnajSt11align_val_t(i32 32, i32 8) builtin
  call void @_ZdaPvSt11align_val_t(i8* %naja, i64 8) builtin
  %nwat = call i8* @_ZnwmSt11align_val_tRKSt9nothrow_t(i64 32, i64 8, i8* %nt) builtin
  call void @_ZdlPvSt11align_val_tRKSt9nothrow_t(i8* %nwat, i64 8, i8* %nt) builtin
  %naat = call i8* @_ZnamSt11align_val_tRKSt9nothrow_t(i64 32, i64 8, i8* %nt) builtin
  call void @_ZdaPvSt11align_val_tRKSt9nothrow_t(i8* %naat, i64 8, i8* %nt) builtin
  %nwjat = call i8* @_ZnwjSt11align_val_tRKSt9nothrow_t(i32 32, i32 8, i8* %nt) builtin
  call void @_ZdlPvSt11align_val_tRKSt9nothrow_t(i8* %nwjat, i64 8, i8* %nt) builtin
  %najat = call i8* @_ZnajSt11align_val_tRKSt9nothrow_t(i32 32, i32 8, i8* %nt) builtin
  call void @_ZdaPvSt11align_val_tRKSt9nothrow_t(i8* %najat, i64 8, i8* %nt) builtin
  %nwa2 = call i8* @_ZnwmSt11align_val_t(i64 32, i64 8) builtin
  call void @_ZdlPvmSt11align_val_t(i8* %nwa2, i64 32, i64 8) builtin
  %nwja2 = call i8* @_ZnwjSt11align_val_t(i32 32, i32 8) builtin
  call void @_ZdlPvjSt11align_val_t(i8* %nwa2, i32 32, i32 8) builtin
  %naa2 = call i8* @_ZnamSt11align_val_t(i64 32, i64 8) builtin
  call void @_ZdaPvmSt11align_val_t(i8* %naa2, i64 32, i64 8) builtin
  %naja2 = call i8* @_ZnajSt11align_val_t(i32 32, i32 8) builtin
  call void @_ZdaPvjSt11align_val_t(i8* %naja2, i32 32, i32 8) builtin

  ; Check that the alignment assume does not prevent the removal.
  %nwa3 = call i8* @_ZnwmSt11align_val_t(i64 32, i64 16) builtin
  call void @llvm.assume(i1 true) [ "align"(i8* %nwa3, i64 16) ]
  call void @_ZdlPvmSt11align_val_t(i8* %nwa3, i64 32, i64 16) builtin

  ret void
}

declare noalias i8* @"\01??2@YAPEAX_K@Z"(i64) nobuiltin
declare void @"\01??3@YAXPEAX@Z"(i8*) nobuiltin

define void @test9() {
; CHECK-LABEL: @test9(
; CHECK-NEXT:    ret void
;
  %new_long_long = call noalias i8* @"\01??2@YAPEAX_K@Z"(i64 32) builtin
  call void @"\01??3@YAXPEAX@Z"(i8* %new_long_long) builtin
  ret void
}

define void @test10()  {
; CHECK-LABEL: @test10(
; CHECK-NEXT:    call void @_ZdlPv(i8* null)
; CHECK-NEXT:    ret void
;
  call void @_ZdlPv(i8* null)
  ret void
}

define void @test11() {
; CHECK-LABEL: @test11(
; CHECK-NEXT:    [[CALL:%.*]] = call dereferenceable(8) i8* @_Znwm(i64 8) #7
; CHECK-NEXT:    call void @_ZdlPv(i8* nonnull [[CALL]])
; CHECK-NEXT:    ret void
;
  %call = call i8* @_Znwm(i64 8) builtin
  call void @_ZdlPv(i8* %call)
  ret void
}

;; Check that the optimization that moves a call to free in its predecessor
;; block (see test6) also happens when noop casts are involved.
define void @test12(i32* %foo) minsize {
; CHECK-LABEL: @test12(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq i32* [[FOO:%.*]], null
; CHECK-NEXT:    [[BITCAST:%.*]] = bitcast i32* [[FOO]] to i8*
; CHECK-NEXT:    tail call void @free(i8* [[BITCAST]])
; CHECK-NEXT:    br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]]
; CHECK:       if.then:
; CHECK-NEXT:    br label [[IF_END]]
; CHECK:       if.end:
; CHECK-NEXT:    ret void
;
;; Everything before the call to free should have been moved as well.
;; Call to free moved
;; Block is now empty and may be simplified by simplifycfg
entry:
  %tobool = icmp eq i32* %foo, null
  br i1 %tobool, label %if.end, label %if.then

if.then:                                          ; preds = %entry
  %bitcast = bitcast i32* %foo to i8*
  tail call void @free(i8* %bitcast)
  br label %if.end

if.end:                                           ; preds = %entry, %if.then
  ret void
}