llvm/test/Transforms/InstCombine/malloc-free.ll

; 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* noundef nonnull align 1 dereferenceable(32) [[PTR:%.*]], i8* noundef nonnull align 1 dereferenceable(32) [[A]], i32 32, i1 false)
; CHECK-NEXT:    call void @llvm.memmove.p0i8.p0i8.i32(i8* noundef nonnull align 1 dereferenceable(32) [[PTR]], i8* noundef 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
}

;; 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
}

;; Test that nonnull-implying attributes on the parameter are adjusted when the
;; call is moved, since they may no longer be valid and result in miscompiles if
;; kept unchanged.
define void @test_nonnull_free_move(i8* %foo) minsize {
; CHECK-LABEL: @test_nonnull_free_move(
; 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
;
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* nonnull %foo)
  br label %if.end

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

define void @test_dereferenceable_free_move(i8* %foo) minsize {
; CHECK-LABEL: @test_dereferenceable_free_move(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq i8* [[FOO:%.*]], null
; CHECK-NEXT:    tail call void @free(i8* dereferenceable_or_null(4) [[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
;
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* dereferenceable(4) %foo)
  br label %if.end

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

define void @test_nonnull_dereferenceable_free_move(i8* %foo) minsize {
; CHECK-LABEL: @test_nonnull_dereferenceable_free_move(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq i8* [[FOO:%.*]], null
; CHECK-NEXT:    tail call void @free(i8* dereferenceable_or_null(16) [[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
;
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* nonnull dereferenceable(16) %foo)
  br label %if.end

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

; The next four tests cover the semantics of the nofree attributes.  These
; are thought to be legal transforms, but an implementation thereof has
; been reverted once due to difficult to isolate fallout.

; TODO: Freeing a no-free pointer -> %foo must be null
define void @test13(i8* nofree %foo) {
; CHECK-LABEL: @test13(
; CHECK-NEXT:    call void @free(i8* [[FOO:%.*]])
; CHECK-NEXT:    ret void
;
  call void @free(i8* %foo)
  ret void
}

; TODO: Freeing a no-free pointer -> %foo must be null
define void @test14(i8* %foo) nofree {
; CHECK-LABEL: @test14(
; CHECK-NEXT:    call void @free(i8* [[FOO:%.*]])
; CHECK-NEXT:    ret void
;
  call void @free(i8* %foo)
  ret void
}

; TODO: free call marked no-free ->  %foo must be null
define void @test15(i8* %foo) {
; CHECK-LABEL: @test15(
; CHECK-NEXT:    call void @free(i8* [[FOO:%.*]]) #[[ATTR5:[0-9]+]]
; CHECK-NEXT:    ret void
;
  call void @free(i8* %foo) nofree
  ret void
}

; TODO: freeing a nonnull nofree pointer -> full UB
define void @test16(i8* nonnull nofree %foo) {
; CHECK-LABEL: @test16(
; CHECK-NEXT:    call void @free(i8* [[FOO:%.*]])
; CHECK-NEXT:    ret void
;
  call void @free(i8* %foo)
  ret void
}