RPCSX/llvm
1
0
Fork 0
mirror of https://github.com/RPCSX/llvm.git synced 2024-12-15 16:09:02 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

PR 18466: Fix ARM Pseudo Expansion

Browse Source 
When expanding neon pseudo stores, it may miss the implicit uses of sub
regs, which may cause post RA scheduler reorder instructions that
breakes anti dependency.

For example:
  VST1d64QPseudo %R0<kill>, 16, %Q9_Q10, pred:14, pred:%noreg
  will be expanded to
    VST1d64Q %R0<kill>, 16, %D18, pred:14, pred:%noreg;

An instruction that defines %D20 may be scheduled before the store by
mistake.

This patches adds implicit uses for such case. For the example above, it
emits:
  VST1d64Q %R0<kill>, 8, %D18, pred:14, pred:%noreg, %Q9_Q10<imp-use>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199282 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Weiming Zhao 2014-01-15 01:32:12 +00:00
parent 0be7e6ffb1
commit 2a0c41756b
2 changed files with 59 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
lib/Target/ARM/ARMExpandPseudoInsts.cpp
View File

@ -479,6 +479,8 @@ void ARMExpandPseudo::ExpandVST(MachineBasicBlock::iterator &MBBI) {
if (SrcIsKill && !SrcIsUndef) // Add an implicit kill for the super-reg.
MIB->addRegisterKilled(SrcReg, TRI, true);
else if (!SrcIsUndef)
MIB.addReg(SrcReg, RegState::Implicit); // Add implicit uses for src reg.
TransferImpOps(MI, MIB, MIB);
// Transfer memoperands.
@ -604,8 +606,8 @@ void ARMExpandPseudo::ExpandVTBL(MachineBasicBlock::iterator &MBBI,
MIB.addOperand(MI.getOperand(OpIdx++));
MIB.addOperand(MI.getOperand(OpIdx++));
if (SrcIsKill) // Add an implicit kill for the super-reg.
MIB->addRegisterKilled(SrcReg, TRI, true);
// Add an implicit kill and use for the super-reg.
MIB.addReg(SrcReg, RegState::Implicit | getKillRegState(SrcIsKill));
TransferImpOps(MI, MIB, MIB);
MI.eraseFromParent();
}

55
test/CodeGen/ARM/2014-01-09-pseudo_expand_implicit_reg.ll Normal file
View File

@ -0,0 +1,55 @@
; RUN: llc < %s -march=arm -mattr=+neon -print-before=post-RA-sched > %t 2>&1 && FileCheck < %t %s
define void @vst(i8* %m, [4 x i64] %v) {
entry:
; CHECK: vst:
; CHECK: VST1d64Q %R{{[0-9]+}}<kill>, 8, %D{{[0-9]+}}, pred:14, pred:%noreg, %Q{{[0-9]+}}_Q{{[0-9]+}}<imp-use>
%v0 = extractvalue [4 x i64] %v, 0
%v1 = extractvalue [4 x i64] %v, 1
%v2 = extractvalue [4 x i64] %v, 2
%v3 = extractvalue [4 x i64] %v, 3
%t0 = bitcast i64 %v0 to <8 x i8>
%t1 = bitcast i64 %v1 to <8 x i8>
%t2 = bitcast i64 %v2 to <8 x i8>
%t3 = bitcast i64 %v3 to <8 x i8>
%s0 = bitcast <8 x i8> %t0 to <1 x i64>
%s1 = bitcast <8 x i8> %t1 to <1 x i64>
%s2 = bitcast <8 x i8> %t2 to <1 x i64>
%s3 = bitcast <8 x i8> %t3 to <1 x i64>
%tmp0 = bitcast <1 x i64> %s2 to i64
%tmp1 = bitcast <1 x i64> %s3 to i64
%n0 = insertelement <2 x i64> undef, i64 %tmp0, i32 0
%n1 = insertelement <2 x i64> %n0, i64 %tmp1, i32 1
call void @llvm.arm.neon.vst4.v1i64(i8* %m, <1 x i64> %s0, <1 x i64> %s1, <1 x i64> %s2, <1 x i64> %s3, i32 8)
call void @bar(<2 x i64> %n1)
ret void
}
%struct.__neon_int8x8x4_t = type { <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8> }
define <8 x i8> @vtbx4(<8 x i8>* %A, %struct.__neon_int8x8x4_t* %B, <8 x i8>* %C) nounwind {
; CHECK: vtbx4:
; CHECK: VTBX4 {{.*}}, pred:14, pred:%noreg, %Q{{[0-9]+}}_Q{{[0-9]+}}<imp-use>
%tmp1 = load <8 x i8>* %A
%tmp2 = load %struct.__neon_int8x8x4_t* %B
%tmp3 = extractvalue %struct.__neon_int8x8x4_t %tmp2, 0
%tmp4 = extractvalue %struct.__neon_int8x8x4_t %tmp2, 1
%tmp5 = extractvalue %struct.__neon_int8x8x4_t %tmp2, 2
%tmp6 = extractvalue %struct.__neon_int8x8x4_t %tmp2, 3
%tmp7 = load <8 x i8>* %C
%tmp8 = call <8 x i8> @llvm.arm.neon.vtbx4(<8 x i8> %tmp1, <8 x i8> %tmp3, <8 x i8> %tmp4, <8 x i8> %tmp5, <8 x i8> %tmp6, <8 x i8> %tmp7)
call void @bar2(%struct.__neon_int8x8x4_t %tmp2, <8 x i8> %tmp8)
ret <8 x i8> %tmp8
}
declare void @llvm.arm.neon.vst4.v1i64(i8*, <1 x i64>, <1 x i64>, <1 x i64>, <1 x i64>, i32)
declare <8 x i8> @llvm.arm.neon.vtbx4(<8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>, <8 x i8>) nounwind readnone
declare void @bar2(%struct.__neon_int8x8x4_t, <8 x i8>)
declare void @bar(<2 x i64> %arg)