forked from OSchip/llvm-project
165 lines
5.0 KiB
LLVM
165 lines
5.0 KiB
LLVM
; RUN: opt -instcombine -S < %s | FileCheck %s
|
|
|
|
@gp = global i32* null, align 8
|
|
|
|
declare i8* @malloc(i64) #1
|
|
|
|
define i1 @compare_global_trivialeq() {
|
|
%m = call i8* @malloc(i64 4)
|
|
%bc = bitcast i8* %m to i32*
|
|
%lgp = load i32*, i32** @gp, align 8
|
|
%cmp = icmp eq i32* %bc, %lgp
|
|
ret i1 %cmp
|
|
; CHECK-LABEL: compare_global_trivialeq
|
|
; CHECK: ret i1 false
|
|
}
|
|
|
|
define i1 @compare_global_trivialne() {
|
|
%m = call i8* @malloc(i64 4)
|
|
%bc = bitcast i8* %m to i32*
|
|
%lgp = load i32*, i32** @gp, align 8
|
|
%cmp = icmp ne i32* %bc, %lgp
|
|
ret i1 %cmp
|
|
; CHECK-LABEL: compare_global_trivialne
|
|
; CHECK: ret i1 true
|
|
}
|
|
|
|
|
|
; Although the %m is marked nocapture in the deopt operand in call to function f,
|
|
; we cannot remove the alloc site: call to malloc
|
|
; The comparison should fold to false irrespective of whether the call to malloc can be elided or not
|
|
declare void @f()
|
|
define i1 @compare_and_call_with_deopt() {
|
|
; CHECK-LABEL: compare_and_call_with_deopt
|
|
%m = call i8* @malloc(i64 24)
|
|
%bc = bitcast i8* %m to i32*
|
|
%lgp = load i32*, i32** @gp, align 8, !nonnull !0
|
|
%cmp = icmp eq i32* %lgp, %bc
|
|
tail call void @f() [ "deopt"(i8* %m) ]
|
|
ret i1 %cmp
|
|
; CHECK: ret i1 false
|
|
}
|
|
|
|
; Same functon as above with deopt operand in function f, but comparison is NE
|
|
define i1 @compare_ne_and_call_with_deopt() {
|
|
; CHECK-LABEL: compare_ne_and_call_with_deopt
|
|
%m = call i8* @malloc(i64 24)
|
|
%bc = bitcast i8* %m to i32*
|
|
%lgp = load i32*, i32** @gp, align 8, !nonnull !0
|
|
%cmp = icmp ne i32* %lgp, %bc
|
|
tail call void @f() [ "deopt"(i8* %m) ]
|
|
ret i1 %cmp
|
|
; CHECK: ret i1 true
|
|
}
|
|
|
|
; Same function as above, but global not marked nonnull, and we cannot fold the comparison
|
|
define i1 @compare_ne_global_maybe_null() {
|
|
; CHECK-LABEL: compare_ne_global_maybe_null
|
|
%m = call i8* @malloc(i64 24)
|
|
%bc = bitcast i8* %m to i32*
|
|
%lgp = load i32*, i32** @gp
|
|
%cmp = icmp ne i32* %lgp, %bc
|
|
tail call void @f() [ "deopt"(i8* %m) ]
|
|
ret i1 %cmp
|
|
; CHECK: ret i1 %cmp
|
|
}
|
|
|
|
; FIXME: The comparison should fold to false since %m escapes (call to function escape)
|
|
; after the comparison.
|
|
declare void @escape(i8*)
|
|
define i1 @compare_and_call_after() {
|
|
; CHECK-LABEL: compare_and_call_after
|
|
%m = call i8* @malloc(i64 24)
|
|
%bc = bitcast i8* %m to i32*
|
|
%lgp = load i32*, i32** @gp, align 8, !nonnull !0
|
|
%cmp = icmp eq i32* %bc, %lgp
|
|
br i1 %cmp, label %escape_call, label %just_return
|
|
|
|
escape_call:
|
|
call void @escape(i8* %m)
|
|
ret i1 true
|
|
|
|
just_return:
|
|
ret i1 %cmp
|
|
}
|
|
|
|
define i1 @compare_distinct_mallocs() {
|
|
%m = call i8* @malloc(i64 4)
|
|
%n = call i8* @malloc(i64 4)
|
|
%cmp = icmp eq i8* %m, %n
|
|
ret i1 %cmp
|
|
; CHECK-LABEL: compare_distinct_mallocs
|
|
; CHECK: ret i1 false
|
|
}
|
|
|
|
; the compare is folded to true since the folding compare looks through bitcasts.
|
|
; call to malloc and the bitcast instructions are elided after that since there are no uses of the malloc
|
|
define i1 @compare_samepointer_under_bitcast() {
|
|
%m = call i8* @malloc(i64 4)
|
|
%bc = bitcast i8* %m to i32*
|
|
%bcback = bitcast i32* %bc to i8*
|
|
%cmp = icmp eq i8* %m, %bcback
|
|
ret i1 %cmp
|
|
; CHECK-LABEL: compare_samepointer_under_bitcast
|
|
; CHECK: ret i1 true
|
|
}
|
|
|
|
; the compare is folded to true since the folding compare looks through bitcasts.
|
|
; The malloc call for %m cannot be elided since it is used in the call to function f.
|
|
define i1 @compare_samepointer_escaped() {
|
|
%m = call i8* @malloc(i64 4)
|
|
%bc = bitcast i8* %m to i32*
|
|
%bcback = bitcast i32* %bc to i8*
|
|
%cmp = icmp eq i8* %m, %bcback
|
|
call void @f() [ "deopt"(i8* %m) ]
|
|
ret i1 %cmp
|
|
; CHECK-LABEL: compare_samepointer_escaped
|
|
; CHECK-NEXT: %m = call i8* @malloc(i64 4)
|
|
; CHECK-NEXT: call void @f() [ "deopt"(i8* %m) ]
|
|
; CHECK: ret i1 true
|
|
}
|
|
|
|
; Technically, we can fold the %cmp2 comparison, even though %m escapes through
|
|
; the ret statement since `ret` terminates the function and we cannot reach from
|
|
; the ret to cmp.
|
|
; FIXME: Folding this %cmp2 when %m escapes through ret could be an issue with
|
|
; cross-threading data dependencies since we do not make the distinction between
|
|
; atomic and non-atomic loads in capture tracking.
|
|
define i8* @compare_ret_escape(i8* %c) {
|
|
%m = call i8* @malloc(i64 4)
|
|
%n = call i8* @malloc(i64 4)
|
|
%cmp = icmp eq i8* %n, %c
|
|
br i1 %cmp, label %retst, label %chk
|
|
|
|
retst:
|
|
ret i8* %m
|
|
|
|
chk:
|
|
%bc = bitcast i8* %m to i32*
|
|
%lgp = load i32*, i32** @gp, align 8, !nonnull !0
|
|
%cmp2 = icmp eq i32* %bc, %lgp
|
|
br i1 %cmp2, label %retst, label %chk2
|
|
|
|
chk2:
|
|
ret i8* %n
|
|
; CHECK-LABEL: compare_ret_escape
|
|
; CHECK: %cmp = icmp eq i8* %n, %c
|
|
; CHECK: %cmp2 = icmp eq i32* %bc, %lgp
|
|
}
|
|
|
|
; The malloc call for %m cannot be elided since it is used in the call to function f.
|
|
; However, the cmp can be folded to true as %n doesnt escape and %m, %n are distinct allocations
|
|
define i1 @compare_distinct_pointer_escape() {
|
|
%m = call i8* @malloc(i64 4)
|
|
%n = call i8* @malloc(i64 4)
|
|
tail call void @f() [ "deopt"(i8* %m) ]
|
|
%cmp = icmp ne i8* %m, %n
|
|
ret i1 %cmp
|
|
; CHECK-LABEL: compare_distinct_pointer_escape
|
|
; CHECK-NEXT: %m = call i8* @malloc(i64 4)
|
|
; CHECK-NEXT: tail call void @f() [ "deopt"(i8* %m) ]
|
|
; CHECK-NEXT: ret i1 true
|
|
}
|
|
|
|
!0 = !{}
|