Fix PR7156. If the sources of a REG_SEQUENCE are all IMPLICIT_DEF's. Replace it with an IMPLICIT_DEF rather than deleting it or else it would be left without a def.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103984 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2010-05-17 22:09:49 +00:00
parent 47006be498
commit 44bfdd3d78
2 changed files with 57 additions and 2 deletions

View File

@ -1238,6 +1238,7 @@ bool TwoAddressInstructionPass::EliminateRegSequences() {
llvm_unreachable(0);
}
bool IsImpDef = true;
SmallVector<unsigned, 4> RealSrcs;
SmallSet<unsigned, 4> Seen;
for (unsigned i = 1, e = MI->getNumOperands(); i < e; i += 2) {
@ -1253,6 +1254,7 @@ bool TwoAddressInstructionPass::EliminateRegSequences() {
DefMI->eraseFromParent();
continue;
}
IsImpDef = false;
// Remember EXTRACT_SUBREG sources. These might be candidate for
// coalescing.
@ -1297,8 +1299,15 @@ bool TwoAddressInstructionPass::EliminateRegSequences() {
UpdateRegSequenceSrcs(SrcReg, DstReg, SubIdx, MRI);
}
DEBUG(dbgs() << "Eliminated: " << *MI);
MI->eraseFromParent();
if (IsImpDef) {
DEBUG(dbgs() << "Turned: " << *MI << " into an IMPLICIT_DEF");
MI->setDesc(TII->get(TargetOpcode::IMPLICIT_DEF));
for (int j = MI->getNumOperands() - 1, ee = 0; j > ee; --j)
MI->RemoveOperand(j);
} else {
DEBUG(dbgs() << "Eliminated: " << *MI);
MI->eraseFromParent();
}
// Try coalescing some EXTRACT_SUBREG instructions.
CoalesceExtSubRegs(RealSrcs, DstReg);

View File

@ -185,6 +185,50 @@ entry:
ret void
}
; PR7156
define arm_aapcs_vfpcc i32 @t8() nounwind {
; CHECK: t8:
; CHECK: vrsqrte.f32 q0, q0
bb.nph55.bb.nph55.split_crit_edge:
br label %bb3
bb3: ; preds = %bb3, %bb.nph55.bb.nph55.split_crit_edge
br i1 undef, label %bb5, label %bb3
bb5: ; preds = %bb3
br label %bb.i25
bb.i25: ; preds = %bb.i25, %bb5
%0 = shufflevector <2 x float> undef, <2 x float> undef, <4 x i32> <i32 0, i32 1, i32 2, i32 3> ; <<4 x float>> [#uses=1]
%1 = call <4 x float> @llvm.arm.neon.vrsqrte.v4f32(<4 x float> %0) nounwind ; <<4 x float>> [#uses=1]
%2 = fmul <4 x float> %1, undef ; <<4 x float>> [#uses=1]
%3 = fmul <4 x float> undef, %2 ; <<4 x float>> [#uses=1]
%tmp26.i = bitcast <4 x float> %3 to <2 x double> ; <<2 x double>> [#uses=1]
%4 = extractelement <2 x double> %tmp26.i, i32 0 ; <double> [#uses=1]
%5 = bitcast double %4 to <2 x float> ; <<2 x float>> [#uses=1]
%6 = extractelement <2 x float> %5, i32 1 ; <float> [#uses=1]
store float %6, float* undef, align 4
br i1 undef, label %bb6, label %bb.i25
bb6: ; preds = %bb.i25
br i1 undef, label %bb7, label %bb14
bb7: ; preds = %bb6
br label %bb.i49
bb.i49: ; preds = %bb.i49, %bb7
br i1 undef, label %bb.i19, label %bb.i49
bb.i19: ; preds = %bb.i19, %bb.i49
br i1 undef, label %exit, label %bb.i19
exit: ; preds = %bb.i19
unreachable
bb14: ; preds = %bb6
ret i32 0
}
declare <4 x i32> @llvm.arm.neon.vld1.v4i32(i8*) nounwind readonly
declare <8 x i16> @llvm.arm.neon.vld1.v8i16(i8*) nounwind readonly
@ -209,4 +253,6 @@ declare %struct.__neon_int16x8x2_t @llvm.arm.neon.vld2lane.v8i16(i8*, <8 x i16>,
declare void @llvm.arm.neon.vst2.v4i32(i8*, <4 x i32>, <4 x i32>) nounwind
declare <4 x float> @llvm.arm.neon.vrsqrte.v4f32(<4 x float>) nounwind readnone
declare void @llvm.trap() nounwind