RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-25 20:23:11 +01:00
Code Issues Projects Releases Wiki Activity

[ConstantFolding] check applicability of AllOnes constant creation first

Browse Source 
The getAllOnesValue can only handle things that are bitcast from a
ConstantInt, while here we bitcast through a pointer, so we may see more
complex objects (like Array or Struct).

Differential Revision: https://reviews.llvm.org/D83870

(cherry picked from commit 8b354cc8db413f596c95b4f3240fabaa3e2c931e)
This commit is contained in:
Jameson Nash 2020-07-15 09:17:42 -04:00 committed by Hans Wennborg
parent 589287d15e
commit 014e600caa
2 changed files with 52 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
lib/Analysis/ConstantFolding.cpp
View File

@ -342,8 +342,12 @@ Constant *llvm::ConstantFoldLoadThroughBitcast(Constant *C, Type *DestTy,
// pointers legally).
if (C->isNullValue() && !DestTy->isX86_MMXTy())
return Constant::getNullValue(DestTy);
if (C->isAllOnesValue() && !DestTy->isX86_MMXTy() &&
!DestTy->isPtrOrPtrVectorTy()) // Don't get ones for ptr types!
if (C->isAllOnesValue() &&
(DestTy->isIntegerTy() || DestTy->isFloatingPointTy() ||
DestTy->isVectorTy()) &&
!DestTy->isX86_MMXTy() && !DestTy->isPtrOrPtrVectorTy())
// Get ones when the input is trivial, but
// only for supported types inside getAllOnesValue.
return Constant::getAllOnesValue(DestTy);
// If the type sizes are the same and a cast is legal, just directly

46
test/Analysis/ConstantFolding/allones.ll Normal file
View File

@ -0,0 +1,46 @@
; RUN: opt -early-cse -S -o - %s | FileCheck %s
target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64-ni:2"
target triple = "armv7-unknown-linux-gnueabi"
%struct.anon = type { i32 }
@onesstruct = private constant %struct.anon { i32 -1 }, align 4
define i32 @allones_struct() {
; CHECK-LABEL: @allones_struct()
; CHECK-NEXT: %1 = load [1 x i32], [1 x i32]* bitcast (%struct.anon* @onesstruct to [1 x i32]*), align 4
; CHECK-NEXT: %2 = extractvalue [1 x i32] %1, 0
; CHECK-NEXT: ret i32 %2
%1 = load [1 x i32], [1 x i32]* bitcast (%struct.anon* @onesstruct to [1 x i32]*), align 4
%2 = extractvalue [1 x i32] %1, 0
ret i32 %2
}
define i32 @allones_int() {
; CHECK-LABEL: @allones_int()
; CHECK-NEXT: ret i32 -1
%1 = load i32, i32* bitcast (%struct.anon* @onesstruct to i32*), align 4
ret i32 %1
}
define i32* @allones_ptr() {
; CHECK-LABEL: @allones_ptr()
; CHECK-NEXT: ret i32* inttoptr (i32 -1 to i32*)
%1 = load i32*, i32** bitcast (%struct.anon* @onesstruct to i32**), align 4
ret i32* %1
}
define i32 addrspace(1)* @allones_ptr1() {
; CHECK-LABEL: @allones_ptr1()
; CHECK-NEXT: ret i32 addrspace(1)* inttoptr (i32 -1 to i32 addrspace(1)*)
%1 = load i32 addrspace(1)*, i32 addrspace(1)** bitcast (%struct.anon* @onesstruct to i32 addrspace(1)**), align 4
ret i32 addrspace(1)* %1
}
define i32 addrspace(2)* @allones_ptr2() {
; CHECK-LABEL: @allones_ptr2()
; CHECK-NEXT: %1 = load i32 addrspace(2)*, i32 addrspace(2)** bitcast (%struct.anon* @onesstruct to i32 addrspace(2)**), align 4
; CHECK-NEXT: ret i32 addrspace(2)* %1
%1 = load i32 addrspace(2)*, i32 addrspace(2)** bitcast (%struct.anon* @onesstruct to i32 addrspace(2)**), align 4
ret i32 addrspace(2)* %1
}