TwoAddressInstructionPass::CoalesceExtSubRegs can insert INSERT_SUBREG

instructions, but it doesn't really understand live ranges, so the first
INSERT_SUBREG uses an implicitly defined register.

Fix it in LiveVariableAnalysis by adding the <undef> flag.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106333 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2010-06-18 22:29:44 +00:00
parent 6a5e2832d0
commit 0465bcffbb
2 changed files with 36 additions and 1 deletions

View File

@ -329,9 +329,16 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
MachineInstr *CopyMI = NULL;
unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
if (mi->isExtractSubreg() || mi->isInsertSubreg() || mi->isSubregToReg() ||
tii_->isMoveInstr(*mi, SrcReg, DstReg, SrcSubReg, DstSubReg))
tii_->isMoveInstr(*mi, SrcReg, DstReg, SrcSubReg, DstSubReg)) {
CopyMI = mi;
// Some of the REG_SEQUENCE lowering in TwoAddressInstrPass creates
// implicit defs without really knowing. It shows up as INSERT_SUBREG
// using an undefined register.
if (mi->isInsertSubreg())
mi->getOperand(1).setIsUndef();
}
VNInfo *ValNo = interval.getNextValue(defIndex, CopyMI, true,
VNInfoAllocator);
assert(ValNo->id == 0 && "First value in interval is not 0?");

View File

@ -19,3 +19,31 @@ entry:
}
declare void @llvm.arm.neon.vst4.v4i32(i8*, <4 x i32>, <4 x i32>, <4 x i32>, <4 x i32>) nounwind
@sbuf = common global [16 x i32] zeroinitializer, align 16 ; <[16 x i32]*> [#uses=5]
@dbuf = common global [16 x i32] zeroinitializer ; <[16 x i32]*> [#uses=2]
; This function creates 4 chained INSERT_SUBREGS and then invokes the register scavenger.
; The first INSERT_SUBREG needs an <undef> use operand for that to work.
define arm_apcscc i32 @main() nounwind {
bb.nph:
br label %bb
bb: ; preds = %bb, %bb.nph
%0 = phi i32 [ 0, %bb.nph ], [ %1, %bb ] ; <i32> [#uses=4]
%scevgep = getelementptr [16 x i32]* @sbuf, i32 0, i32 %0 ; <i32*> [#uses=1]
%scevgep5 = getelementptr [16 x i32]* @dbuf, i32 0, i32 %0 ; <i32*> [#uses=1]
store i32 %0, i32* %scevgep, align 4
store i32 -1, i32* %scevgep5, align 4
%1 = add nsw i32 %0, 1 ; <i32> [#uses=2]
%exitcond = icmp eq i32 %1, 16 ; <i1> [#uses=1]
br i1 %exitcond, label %bb2, label %bb
bb2: ; preds = %bb
%2 = load <4 x i32>* bitcast ([16 x i32]* @sbuf to <4 x i32>*), align 16 ; <<4 x i32>> [#uses=1]
%3 = load <4 x i32>* bitcast (i32* getelementptr inbounds ([16 x i32]* @sbuf, i32 0, i32 4) to <4 x i32>*), align 16 ; <<4 x i32>> [#uses=1]
%4 = load <4 x i32>* bitcast (i32* getelementptr inbounds ([16 x i32]* @sbuf, i32 0, i32 8) to <4 x i32>*), align 16 ; <<4 x i32>> [#uses=1]
%5 = load <4 x i32>* bitcast (i32* getelementptr inbounds ([16 x i32]* @sbuf, i32 0, i32 12) to <4 x i32>*), align 16 ; <<4 x i32>> [#uses=1]
tail call void @llvm.arm.neon.vst4.v4i32(i8* bitcast ([16 x i32]* @dbuf to i8*), <4 x i32> %2, <4 x i32> %3, <4 x i32> %4, <4 x i32> %5) nounwind
ret i32 0
}