vcp-accesses-memory.ll
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; RUN: opt -S -wholeprogramdevirt %s | FileCheck %s
; RUN: opt -S -passes=wholeprogramdevirt %s | FileCheck %s
target datalayout = "e-p:64:64"
target triple = "x86_64-unknown-linux-gnu"
@vt1 = constant [2 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf1a to i8*), i8* bitcast (i32 (i8*, i32)* @vf1b to i8*)], !type !0
@vt2 = constant [2 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2a to i8*), i8* bitcast (i32 (i8*, i32)* @vf2b to i8*)], !type !0
@sink = external global i32
define i32 @vf1a(i8* %this, i32 %arg) {
store i32 %arg, i32* @sink
ret i32 %arg
}
define i32 @vf2a(i8* %this, i32 %arg) {
store i32 %arg, i32* @sink
ret i32 %arg
}
define i32 @vf1b(i8* %this, i32 %arg) {
ret i32 %arg
}
define i32 @vf2b(i8* %this, i32 %arg) {
ret i32 %arg
}
; Test that we don't apply VCP if the virtual function body accesses memory,
; even if the function returns a constant.
; CHECK: define i32 @call1
define i32 @call1(i8* %obj) {
%vtableptr = bitcast i8* %obj to [1 x i8*]**
%vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
%vtablei8 = bitcast [1 x i8*]* %vtable to i8*
%p = call i1 @llvm.type.test(i8* %vtablei8, metadata !"typeid")
call void @llvm.assume(i1 %p)
%fptrptr = getelementptr [1 x i8*], [1 x i8*]* %vtable, i32 0, i32 0
%fptr = load i8*, i8** %fptrptr
%fptr_casted = bitcast i8* %fptr to i32 (i8*, i32)*
; CHECK: call i32 %
%result = call i32 %fptr_casted(i8* %obj, i32 1)
ret i32 %result
}
; Test that we can apply VCP regardless of the function attributes by analyzing
; the function body itself.
; CHECK: define i32 @call2
define i32 @call2(i8* %obj) {
%vtableptr = bitcast i8* %obj to [1 x i8*]**
%vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
%vtablei8 = bitcast [1 x i8*]* %vtable to i8*
%p = call i1 @llvm.type.test(i8* %vtablei8, metadata !"typeid")
call void @llvm.assume(i1 %p)
%fptrptr = getelementptr [1 x i8*], [1 x i8*]* %vtable, i32 0, i32 1
%fptr = load i8*, i8** %fptrptr
%fptr_casted = bitcast i8* %fptr to i32 (i8*, i32)*
%result = call i32 %fptr_casted(i8* %obj, i32 1)
; CHECK: ret i32 1
ret i32 %result
}
declare i1 @llvm.type.test(i8*, metadata)
declare void @llvm.assume(i1)
!0 = !{i32 0, !"typeid"}