Avoid processing early clobbers twice in RegAllocFast.

Early clobbers defining a virtual register were first alocated to a physreg and
then processed as a physreg EC, spilling the virtreg.

This fixes PR7382.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105998 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2010-06-15 16:20:57 +00:00
parent 40d07bbebb
commit 75ac4d9c2d
2 changed files with 37 additions and 3 deletions

View File

@ -708,7 +708,8 @@ void RAFast::AllocateBasicBlock() {
if (MO.isUse()) {
usePhysReg(MO);
} else if (MO.isEarlyClobber()) {
definePhysReg(MI, Reg, MO.isDead() ? regFree : regReserved);
definePhysReg(MI, Reg, (MO.isImplicit() || MO.isDead()) ?
regFree : regReserved);
PhysECs.push_back(Reg);
}
}
@ -731,8 +732,11 @@ void RAFast::AllocateBasicBlock() {
// Note: defineVirtReg may invalidate MO.
LiveRegMap::iterator LRI = defineVirtReg(MI, i, Reg, 0);
unsigned PhysReg = LRI->second.PhysReg;
setPhysReg(MI, i, PhysReg);
if (setPhysReg(MI, i, PhysReg))
VirtDead.push_back(Reg);
PhysECs.push_back(PhysReg);
// Don't attempt coalescing when earlyclobbers are present.
CopyDst = 0;
}
}
@ -767,7 +771,8 @@ void RAFast::AllocateBasicBlock() {
// Allocate defs and collect dead defs.
for (unsigned i = 0; i != DefOpEnd; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg() || !MO.isDef() || !MO.getReg()) continue;
if (!MO.isReg() || !MO.isDef() || !MO.getReg() || MO.isEarlyClobber())
continue;
unsigned Reg = MO.getReg();
if (TargetRegisterInfo::isPhysicalRegister(Reg)) {

View File

@ -0,0 +1,29 @@
; RUN: llc -regalloc=fast < %s | FileCheck %s
; PR7382
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-unknown-linux-gnu"
@.str = private constant [23 x i8] c"This should be -1: %d\0A\00" ; <[23 x i8]*> [#uses=1]
define i32 @main() {
entry:
%retval = alloca i32, align 4 ; <i32*> [#uses=3]
%v = alloca i32, align 4 ; <i32*> [#uses=3]
store i32 0, i32* %retval
%zero = load i32* %retval
; The earlyclobber register EC0 should not be spilled before the inline asm.
; Yes, check-not can refer to FileCheck variables defined in the future.
; CHECK-NOT: [[EC0]]{{.*}}(%rsp)
; CHECK: bsr {{[^,]*}}, [[EC0:%...]]
%0 = call i32 asm "bsr $1, $0\0A\09cmovz $2, $0", "=&r,ro,r,~{cc},~{dirflag},~{fpsr},~{flags}"(i32 %zero, i32 -1) nounwind, !srcloc !0 ; <i32> [#uses=1]
store i32 %0, i32* %v
%tmp = load i32* %v ; <i32> [#uses=1]
%call1 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([23 x i8]* @.str, i32 0, i32 0), i32 %tmp) ; <i32> [#uses=0]
store i32 0, i32* %retval
%1 = load i32* %retval ; <i32> [#uses=1]
ret i32 %0
}
declare i32 @printf(i8*, ...)
!0 = metadata !{i32 191}