test/Transforms/InstCombine/malloc-free.ll - llvm-project/llvm - Git at Google

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -passes=instcombine -S | FileCheck %s
 ; PR1201

 target datalayout = "p:32:32:32"

 define i32 @main(i32 %argc, ptr %argv) {
 ; CHECK-LABEL: @main(
 ; CHECK-NEXT:    ret i32 0
 ;
   %c_19 = alloca ptr
   %malloc_206 = tail call ptr @malloc(i32 mul (i32 ptrtoint (ptr getelementptr (i8, ptr null, i32 1) to i32), i32 10))
   store ptr %malloc_206, ptr %c_19
   %tmp_207 = load ptr, ptr %c_19
   tail call void @free(ptr %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 ptr @aligned_alloc(i32 %alignment, i32 %size)
   store i8 %value, ptr %aligned_allocation
   tail call void @free(ptr %aligned_allocation)
   ret i32 0
 }

 declare noalias ptr @calloc(i32, i32) nounwind allockind("alloc,zeroed") allocsize(0,1) "alloc-family"="malloc"
 declare noalias ptr @malloc(i32) allockind("alloc,uninitialized") allocsize(0) "alloc-family"="malloc"
 declare noalias ptr @aligned_alloc(i32, i32) allockind("alloc,uninitialized,aligned") allocsize(1) "alloc-family"="malloc"
 declare void @free(ptr) allockind("free") "alloc-family"="malloc"

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

 declare void @llvm.lifetime.start.p0(i64, ptr)
 declare void @llvm.lifetime.end.p0(i64, ptr)
 declare i64 @llvm.objectsize.i64(ptr, i1)
 declare void @llvm.memcpy.p0.p0.i32(ptr nocapture, ptr nocapture, i32, i1) nounwind
 declare void @llvm.memmove.p0.p0.i32(ptr nocapture, ptr nocapture, i32, i1) nounwind
 declare void @llvm.memset.p0.i32(ptr, i8, i32, i1) nounwind

 define void @test3(ptr %src) {
 ; CHECK-LABEL: @test3(
 ; CHECK-NEXT:    ret void
 ;
   %a = call noalias ptr @malloc(i32 10)
   call void @llvm.lifetime.start.p0(i64 10, ptr %a)
   call void @llvm.lifetime.end.p0(i64 10, ptr %a)
   %size = call i64 @llvm.objectsize.i64(ptr %a, i1 true)
   store i8 42, ptr %a
   call void @llvm.memcpy.p0.p0.i32(ptr %a, ptr %src, i32 32, i1 false)
   call void @llvm.memmove.p0.p0.i32(ptr %a, ptr %src, i32 32, i1 false)
   call void @llvm.memset.p0.i32(ptr %a, i8 5, i32 32, i1 false)
   %alloc2 = call noalias ptr @calloc(i32 5, i32 7) nounwind
   %z = icmp ne ptr %alloc2, null
   ret void
 }

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

 define void @test5(ptr %ptr, ptr %esc) {
 ; CHECK-LABEL: @test5(
 ; CHECK-NEXT:    [[A:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
 ; CHECK-NEXT:    [[B:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
 ; CHECK-NEXT:    [[C:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
 ; CHECK-NEXT:    [[D:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
 ; CHECK-NEXT:    [[E:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
 ; CHECK-NEXT:    [[F:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
 ; CHECK-NEXT:    [[G:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
 ; CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i32(ptr noundef nonnull align 1 dereferenceable(32) [[PTR:%.*]], ptr noundef nonnull align 1 dereferenceable(32) [[A]], i32 32, i1 false)
 ; CHECK-NEXT:    call void @llvm.memmove.p0.p0.i32(ptr noundef nonnull align 1 dereferenceable(32) [[PTR]], ptr noundef nonnull align 1 dereferenceable(32) [[B]], i32 32, i1 false)
 ; CHECK-NEXT:    store ptr [[C]], ptr [[ESC:%.*]], align 4
 ; CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i32(ptr [[D]], ptr [[PTR]], i32 32, i1 true)
 ; CHECK-NEXT:    call void @llvm.memmove.p0.p0.i32(ptr [[E]], ptr [[PTR]], i32 32, i1 true)
 ; CHECK-NEXT:    call void @llvm.memset.p0.i32(ptr [[F]], i8 5, i32 32, i1 true)
 ; CHECK-NEXT:    store volatile i8 4, ptr [[G]], align 1
 ; CHECK-NEXT:    ret void
 ;
   %a = call ptr @malloc(i32 700)
   %b = call ptr @malloc(i32 700)
   %c = call ptr @malloc(i32 700)
   %d = call ptr @malloc(i32 700)
   %e = call ptr @malloc(i32 700)
   %f = call ptr @malloc(i32 700)
   %g = call ptr @malloc(i32 700)
   call void @llvm.memcpy.p0.p0.i32(ptr %ptr, ptr %a, i32 32, i1 false)
   call void @llvm.memmove.p0.p0.i32(ptr %ptr, ptr %b, i32 32, i1 false)
   store ptr %c, ptr %esc
   call void @llvm.memcpy.p0.p0.i32(ptr %d, ptr %ptr, i32 32, i1 true)
   call void @llvm.memmove.p0.p0.i32(ptr %e, ptr %ptr, i32 32, i1 true)
   call void @llvm.memset.p0.i32(ptr %f, i8 5, i32 32, i1 true)
   store volatile i8 4, ptr %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(ptr %foo) minsize {
 ; CHECK-LABEL: @test6(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq ptr [[FOO:%.*]], null
 ; CHECK-NEXT:    tail call void @free(ptr [[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 ptr %foo, null
   br i1 %tobool, label %if.end, label %if.then

 if.then:                                          ; preds = %entry
   tail call void @free(ptr %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(ptr %foo) minsize {
 ; CHECK-LABEL: @test12(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq ptr [[FOO:%.*]], null
 ; CHECK-NEXT:    tail call void @free(ptr [[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
 ;
 ;; 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 ptr %foo, null
   br i1 %tobool, label %if.end, label %if.then

 if.then:                                          ; preds = %entry
   tail call void @free(ptr %foo)
   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(ptr %foo) minsize {
 ; CHECK-LABEL: @test_nonnull_free_move(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq ptr [[FOO:%.*]], null
 ; CHECK-NEXT:    tail call void @free(ptr [[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 ptr %foo, null
   br i1 %tobool, label %if.end, label %if.then

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

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

 define void @test_dereferenceable_free_move(ptr %foo) minsize {
 ; CHECK-LABEL: @test_dereferenceable_free_move(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq ptr [[FOO:%.*]], null
 ; CHECK-NEXT:    tail call void @free(ptr 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 ptr %foo, null
   br i1 %tobool, label %if.end, label %if.then

 if.then:                                          ; preds = %entry
   tail call void @free(ptr dereferenceable(4) %foo)
   br label %if.end

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

 define void @test_nonnull_dereferenceable_free_move(ptr %foo) minsize {
 ; CHECK-LABEL: @test_nonnull_dereferenceable_free_move(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq ptr [[FOO:%.*]], null
 ; CHECK-NEXT:    tail call void @free(ptr 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 ptr %foo, null
   br i1 %tobool, label %if.end, label %if.then

 if.then:                                          ; preds = %entry
   tail call void @free(ptr 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(ptr nofree %foo) {
 ; CHECK-LABEL: @test13(
 ; CHECK-NEXT:    call void @free(ptr [[FOO:%.*]])
 ; CHECK-NEXT:    ret void
 ;
   call void @free(ptr %foo)
   ret void
 }

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

 ; TODO: free call marked no-free ->  %foo must be null
 define void @test15(ptr %foo) {
 ; CHECK-LABEL: @test15(
 ; CHECK-NEXT:    call void @free(ptr [[FOO:%.*]]) #[[ATTR8:[0-9]+]]
 ; CHECK-NEXT:    ret void
 ;
   call void @free(ptr %foo) nofree
   ret void
 }

 ; TODO: freeing a nonnull nofree pointer -> full UB
 define void @test16(ptr nonnull nofree %foo) {
 ; CHECK-LABEL: @test16(
 ; CHECK-NEXT:    call void @free(ptr [[FOO:%.*]])
 ; CHECK-NEXT:    ret void
 ;
   call void @free(ptr %foo)
   ret void
 }
	; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
	; RUN: opt < %s -passes=instcombine -S \| FileCheck %s
	; PR1201

	target datalayout = "p:32:32:32"

	define i32 @main(i32 %argc, ptr %argv) {
	; CHECK-LABEL: @main(
	; CHECK-NEXT: ret i32 0
	;
	%c_19 = alloca ptr
	%malloc_206 = tail call ptr @malloc(i32 mul (i32 ptrtoint (ptr getelementptr (i8, ptr null, i32 1) to i32), i32 10))
	store ptr %malloc_206, ptr %c_19
	%tmp_207 = load ptr, ptr %c_19
	tail call void @free(ptr %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 ptr @aligned_alloc(i32 %alignment, i32 %size)
	store i8 %value, ptr %aligned_allocation
	tail call void @free(ptr %aligned_allocation)
	ret i32 0
	}

	declare noalias ptr @calloc(i32, i32) nounwind allockind("alloc,zeroed") allocsize(0,1) "alloc-family"="malloc"
	declare noalias ptr @malloc(i32) allockind("alloc,uninitialized") allocsize(0) "alloc-family"="malloc"
	declare noalias ptr @aligned_alloc(i32, i32) allockind("alloc,uninitialized,aligned") allocsize(1) "alloc-family"="malloc"
	declare void @free(ptr) allockind("free") "alloc-family"="malloc"

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

	declare void @llvm.lifetime.start.p0(i64, ptr)
	declare void @llvm.lifetime.end.p0(i64, ptr)
	declare i64 @llvm.objectsize.i64(ptr, i1)
	declare void @llvm.memcpy.p0.p0.i32(ptr nocapture, ptr nocapture, i32, i1) nounwind
	declare void @llvm.memmove.p0.p0.i32(ptr nocapture, ptr nocapture, i32, i1) nounwind
	declare void @llvm.memset.p0.i32(ptr, i8, i32, i1) nounwind

	define void @test3(ptr %src) {
	; CHECK-LABEL: @test3(
	; CHECK-NEXT: ret void
	;
	%a = call noalias ptr @malloc(i32 10)
	call void @llvm.lifetime.start.p0(i64 10, ptr %a)
	call void @llvm.lifetime.end.p0(i64 10, ptr %a)
	%size = call i64 @llvm.objectsize.i64(ptr %a, i1 true)
	store i8 42, ptr %a
	call void @llvm.memcpy.p0.p0.i32(ptr %a, ptr %src, i32 32, i1 false)
	call void @llvm.memmove.p0.p0.i32(ptr %a, ptr %src, i32 32, i1 false)
	call void @llvm.memset.p0.i32(ptr %a, i8 5, i32 32, i1 false)
	%alloc2 = call noalias ptr @calloc(i32 5, i32 7) nounwind
	%z = icmp ne ptr %alloc2, null
	ret void
	}

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

	define void @test5(ptr %ptr, ptr %esc) {
	; CHECK-LABEL: @test5(
	; CHECK-NEXT: [[A:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
	; CHECK-NEXT: [[B:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
	; CHECK-NEXT: [[C:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
	; CHECK-NEXT: [[D:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
	; CHECK-NEXT: [[E:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
	; CHECK-NEXT: [[F:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
	; CHECK-NEXT: [[G:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
	; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr noundef nonnull align 1 dereferenceable(32) [[PTR:%.*]], ptr noundef nonnull align 1 dereferenceable(32) [[A]], i32 32, i1 false)
	; CHECK-NEXT: call void @llvm.memmove.p0.p0.i32(ptr noundef nonnull align 1 dereferenceable(32) [[PTR]], ptr noundef nonnull align 1 dereferenceable(32) [[B]], i32 32, i1 false)
	; CHECK-NEXT: store ptr [[C]], ptr [[ESC:%.*]], align 4
	; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr [[D]], ptr [[PTR]], i32 32, i1 true)
	; CHECK-NEXT: call void @llvm.memmove.p0.p0.i32(ptr [[E]], ptr [[PTR]], i32 32, i1 true)
	; CHECK-NEXT: call void @llvm.memset.p0.i32(ptr [[F]], i8 5, i32 32, i1 true)
	; CHECK-NEXT: store volatile i8 4, ptr [[G]], align 1
	; CHECK-NEXT: ret void
	;
	%a = call ptr @malloc(i32 700)
	%b = call ptr @malloc(i32 700)
	%c = call ptr @malloc(i32 700)
	%d = call ptr @malloc(i32 700)
	%e = call ptr @malloc(i32 700)
	%f = call ptr @malloc(i32 700)
	%g = call ptr @malloc(i32 700)
	call void @llvm.memcpy.p0.p0.i32(ptr %ptr, ptr %a, i32 32, i1 false)
	call void @llvm.memmove.p0.p0.i32(ptr %ptr, ptr %b, i32 32, i1 false)
	store ptr %c, ptr %esc
	call void @llvm.memcpy.p0.p0.i32(ptr %d, ptr %ptr, i32 32, i1 true)
	call void @llvm.memmove.p0.p0.i32(ptr %e, ptr %ptr, i32 32, i1 true)
	call void @llvm.memset.p0.i32(ptr %f, i8 5, i32 32, i1 true)
	store volatile i8 4, ptr %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(ptr %foo) minsize {
	; CHECK-LABEL: @test6(
	; CHECK-NEXT: entry:
	; CHECK-NEXT: [[TOBOOL:%.]] = icmp eq ptr [[FOO:%.]], null
	; CHECK-NEXT: tail call void @free(ptr [[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 ptr %foo, null
	br i1 %tobool, label %if.end, label %if.then

	if.then: ; preds = %entry
	tail call void @free(ptr %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(ptr %foo) minsize {
	; CHECK-LABEL: @test12(
	; CHECK-NEXT: entry:
	; CHECK-NEXT: [[TOBOOL:%.]] = icmp eq ptr [[FOO:%.]], null
	; CHECK-NEXT: tail call void @free(ptr [[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
	;
	;; 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 ptr %foo, null
	br i1 %tobool, label %if.end, label %if.then

	if.then: ; preds = %entry
	tail call void @free(ptr %foo)
	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(ptr %foo) minsize {
	; CHECK-LABEL: @test_nonnull_free_move(
	; CHECK-NEXT: entry:
	; CHECK-NEXT: [[TOBOOL:%.]] = icmp eq ptr [[FOO:%.]], null
	; CHECK-NEXT: tail call void @free(ptr [[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 ptr %foo, null
	br i1 %tobool, label %if.end, label %if.then

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

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

	define void @test_dereferenceable_free_move(ptr %foo) minsize {
	; CHECK-LABEL: @test_dereferenceable_free_move(
	; CHECK-NEXT: entry:
	; CHECK-NEXT: [[TOBOOL:%.]] = icmp eq ptr [[FOO:%.]], null
	; CHECK-NEXT: tail call void @free(ptr 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 ptr %foo, null
	br i1 %tobool, label %if.end, label %if.then

	if.then: ; preds = %entry
	tail call void @free(ptr dereferenceable(4) %foo)
	br label %if.end

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

	define void @test_nonnull_dereferenceable_free_move(ptr %foo) minsize {
	; CHECK-LABEL: @test_nonnull_dereferenceable_free_move(
	; CHECK-NEXT: entry:
	; CHECK-NEXT: [[TOBOOL:%.]] = icmp eq ptr [[FOO:%.]], null
	; CHECK-NEXT: tail call void @free(ptr 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 ptr %foo, null
	br i1 %tobool, label %if.end, label %if.then

	if.then: ; preds = %entry
	tail call void @free(ptr 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(ptr nofree %foo) {
	; CHECK-LABEL: @test13(
	; CHECK-NEXT: call void @free(ptr [[FOO:%.*]])
	; CHECK-NEXT: ret void
	;
	call void @free(ptr %foo)
	ret void
	}

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

	; TODO: free call marked no-free -> %foo must be null
	define void @test15(ptr %foo) {
	; CHECK-LABEL: @test15(
	; CHECK-NEXT: call void @free(ptr [[FOO:%.*]]) #[[ATTR8:[0-9]+]]
	; CHECK-NEXT: ret void
	;
	call void @free(ptr %foo) nofree
	ret void
	}

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