[llvm] r188540 - [SystemZ] Fix handling of 64-bit memcmp results
Richard Sandiford
rsandifo at linux.vnet.ibm.com
Fri Aug 16 03:55:47 PDT 2013
Author: rsandifo
Date: Fri Aug 16 05:55:47 2013
New Revision: 188540
URL: http://llvm.org/viewvc/llvm-project?rev=188540&view=rev
Log:
[SystemZ] Fix handling of 64-bit memcmp results
Generalize r188163 to cope with return types other than MVT::i32, just
as the existing visitMemCmpCall code did. I've split this out into a
subroutine so that it can be used for other upcoming patches.
I also noticed that I'd used the wrong API to record the out chain.
It's a load that uses DAG.getRoot() rather than getRoot(), so the out
chain should go on PendingLoads. I don't have a testcase for that because
we don't do any interesting scheduling on z yet.
Added:
llvm/trunk/test/CodeGen/SystemZ/memcmp-02.ll
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
llvm/trunk/lib/Target/SystemZ/SystemZInstrInfo.cpp
llvm/trunk/test/CodeGen/SystemZ/memcmp-01.ll
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=188540&r1=188539&r2=188540&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Fri Aug 16 05:55:47 2013
@@ -5448,6 +5448,18 @@ static SDValue getMemCmpLoad(const Value
return LoadVal;
}
+/// processIntegerCallValue - Record the value for an instruction that
+/// produces an integer result, converting the type where necessary.
+void SelectionDAGBuilder::processIntegerCallValue(const Instruction &I,
+ SDValue Value,
+ bool IsSigned) {
+ EVT VT = TM.getTargetLowering()->getValueType(I.getType(), true);
+ if (IsSigned)
+ Value = DAG.getSExtOrTrunc(Value, getCurSDLoc(), VT);
+ else
+ Value = DAG.getZExtOrTrunc(Value, getCurSDLoc(), VT);
+ setValue(&I, Value);
+}
/// visitMemCmpCall - See if we can lower a call to memcmp in an optimized form.
/// If so, return true and lower it, otherwise return false and it will be
@@ -5463,35 +5475,33 @@ bool SelectionDAGBuilder::visitMemCmpCal
!I.getType()->isIntegerTy())
return false;
- const ConstantInt *Size = dyn_cast<ConstantInt>(I.getArgOperand(2));
- if (Size && Size->getZExtValue() == 0) {
+ const Value *Size = I.getArgOperand(2);
+ const ConstantInt *CSize = dyn_cast<ConstantInt>(Size);
+ if (CSize && CSize->getZExtValue() == 0) {
EVT CallVT = TM.getTargetLowering()->getValueType(I.getType(), true);
setValue(&I, DAG.getConstant(0, CallVT));
return true;
}
- const Value *Arg0 = I.getArgOperand(0);
- const Value *Arg1 = I.getArgOperand(1);
- const Value *Arg2 = I.getArgOperand(2);
const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForMemcmp(DAG, getCurSDLoc(), DAG.getRoot(),
- getValue(Arg0), getValue(Arg1), getValue(Arg2),
- MachinePointerInfo(Arg0),
- MachinePointerInfo(Arg1));
+ getValue(LHS), getValue(RHS), getValue(Size),
+ MachinePointerInfo(LHS),
+ MachinePointerInfo(RHS));
if (Res.first.getNode()) {
- setValue(&I, Res.first);
- DAG.setRoot(Res.second);
+ processIntegerCallValue(I, Res.first, true);
+ PendingLoads.push_back(Res.second);
return true;
}
// memcmp(S1,S2,2) != 0 -> (*(short*)LHS != *(short*)RHS) != 0
// memcmp(S1,S2,4) != 0 -> (*(int*)LHS != *(int*)RHS) != 0
- if (Size && IsOnlyUsedInZeroEqualityComparison(&I)) {
+ if (CSize && IsOnlyUsedInZeroEqualityComparison(&I)) {
bool ActuallyDoIt = true;
MVT LoadVT;
Type *LoadTy;
- switch (Size->getZExtValue()) {
+ switch (CSize->getZExtValue()) {
default:
LoadVT = MVT::Other;
LoadTy = 0;
@@ -5499,20 +5509,20 @@ bool SelectionDAGBuilder::visitMemCmpCal
break;
case 2:
LoadVT = MVT::i16;
- LoadTy = Type::getInt16Ty(Size->getContext());
+ LoadTy = Type::getInt16Ty(CSize->getContext());
break;
case 4:
LoadVT = MVT::i32;
- LoadTy = Type::getInt32Ty(Size->getContext());
+ LoadTy = Type::getInt32Ty(CSize->getContext());
break;
case 8:
LoadVT = MVT::i64;
- LoadTy = Type::getInt64Ty(Size->getContext());
+ LoadTy = Type::getInt64Ty(CSize->getContext());
break;
/*
case 16:
LoadVT = MVT::v4i32;
- LoadTy = Type::getInt32Ty(Size->getContext());
+ LoadTy = Type::getInt32Ty(CSize->getContext());
LoadTy = VectorType::get(LoadTy, 4);
break;
*/
@@ -5526,7 +5536,7 @@ bool SelectionDAGBuilder::visitMemCmpCal
// supports unaligned loads of that type. Expanding into byte loads would
// bloat the code.
const TargetLowering *TLI = TM.getTargetLowering();
- if (ActuallyDoIt && Size->getZExtValue() > 4) {
+ if (ActuallyDoIt && CSize->getZExtValue() > 4) {
// TODO: Handle 5 byte compare as 4-byte + 1 byte.
// TODO: Handle 8 byte compare on x86-32 as two 32-bit loads.
if (!TLI->isTypeLegal(LoadVT) ||!TLI->allowsUnalignedMemoryAccesses(LoadVT))
@@ -5539,8 +5549,7 @@ bool SelectionDAGBuilder::visitMemCmpCal
SDValue Res = DAG.getSetCC(getCurSDLoc(), MVT::i1, LHSVal, RHSVal,
ISD::SETNE);
- EVT CallVT = TLI->getValueType(I.getType(), true);
- setValue(&I, DAG.getZExtOrTrunc(Res, getCurSDLoc(), CallVT));
+ processIntegerCallValue(I, Res, false);
return true;
}
}
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h?rev=188540&r1=188539&r2=188540&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h Fri Aug 16 05:55:47 2013
@@ -543,6 +543,9 @@ private:
llvm_unreachable("UserOp2 should not exist at instruction selection time!");
}
+ void processIntegerCallValue(const Instruction &I,
+ SDValue Value, bool IsSigned);
+
void HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB);
/// EmitFuncArgumentDbgValue - If V is an function argument then create
Modified: llvm/trunk/lib/Target/SystemZ/SystemZInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/SystemZ/SystemZInstrInfo.cpp?rev=188540&r1=188539&r2=188540&view=diff
==============================================================================
--- llvm/trunk/lib/Target/SystemZ/SystemZInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/SystemZ/SystemZInstrInfo.cpp Fri Aug 16 05:55:47 2013
@@ -339,7 +339,12 @@ static void eraseIfDead(MachineInstr *MI
static bool removeIPMBasedCompare(MachineInstr *Compare, unsigned SrcReg,
const MachineRegisterInfo *MRI,
const TargetRegisterInfo *TRI) {
+ MachineInstr *LGFR = 0;
MachineInstr *RLL = getDef(SrcReg, MRI);
+ if (RLL && RLL->getOpcode() == SystemZ::LGFR) {
+ LGFR = RLL;
+ RLL = getDef(LGFR->getOperand(1).getReg(), MRI);
+ }
if (!RLL || !isShift(RLL, SystemZ::RLL, 31))
return false;
@@ -362,6 +367,8 @@ static bool removeIPMBasedCompare(Machin
}
Compare->eraseFromParent();
+ if (LGFR)
+ eraseIfDead(LGFR, MRI);
eraseIfDead(RLL, MRI);
eraseIfDead(SRL, MRI);
eraseIfDead(IPM, MRI);
Modified: llvm/trunk/test/CodeGen/SystemZ/memcmp-01.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/SystemZ/memcmp-01.ll?rev=188540&r1=188539&r2=188540&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/SystemZ/memcmp-01.ll (original)
+++ llvm/trunk/test/CodeGen/SystemZ/memcmp-01.ll Fri Aug 16 05:55:47 2013
@@ -1,4 +1,4 @@
-; Test memcmp using CLC.
+; Test memcmp using CLC, with i32 results.
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
Added: llvm/trunk/test/CodeGen/SystemZ/memcmp-02.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/SystemZ/memcmp-02.ll?rev=188540&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/SystemZ/memcmp-02.ll (added)
+++ llvm/trunk/test/CodeGen/SystemZ/memcmp-02.ll Fri Aug 16 05:55:47 2013
@@ -0,0 +1,135 @@
+; Test memcmp using CLC, with i64 results.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+declare i64 @memcmp(i8 *%src1, i8 *%src2, i64 %size)
+
+; Zero-length comparisons should be optimized away.
+define i64 @f1(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f1:
+; CHECK: lghi %r2, 0
+; CHECK: br %r14
+ %res = call i64 @memcmp(i8 *%src1, i8 *%src2, i64 0)
+ ret i64 %res
+}
+
+; Check a case where the result is used as an integer.
+define i64 @f2(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f2:
+; CHECK: clc 0(2,%r2), 0(%r3)
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: srl [[REG]], 28
+; CHECK: rll [[REG]], [[REG]], 31
+; CHECK: lgfr %r2, [[REG]]
+; CHECK: br %r14
+ %res = call i64 @memcmp(i8 *%src1, i8 *%src2, i64 2)
+ ret i64 %res
+}
+
+; Check a case where the result is tested for equality.
+define void @f3(i8 *%src1, i8 *%src2, i64 *%dest) {
+; CHECK-LABEL: f3:
+; CHECK: clc 0(3,%r2), 0(%r3)
+; CHECK-NEXT: je {{\..*}}
+; CHECK: br %r14
+ %res = call i64 @memcmp(i8 *%src1, i8 *%src2, i64 3)
+ %cmp = icmp eq i64 %res, 0
+ br i1 %cmp, label %exit, label %store
+
+store:
+ store i64 0, i64 *%dest
+ br label %exit
+
+exit:
+ ret void
+}
+
+; Check a case where the result is tested for inequality.
+define void @f4(i8 *%src1, i8 *%src2, i64 *%dest) {
+; CHECK-LABEL: f4:
+; CHECK: clc 0(4,%r2), 0(%r3)
+; CHECK-NEXT: jlh {{\..*}}
+; CHECK: br %r14
+entry:
+ %res = call i64 @memcmp(i8 *%src1, i8 *%src2, i64 4)
+ %cmp = icmp ne i64 %res, 0
+ br i1 %cmp, label %exit, label %store
+
+store:
+ store i64 0, i64 *%dest
+ br label %exit
+
+exit:
+ ret void
+}
+
+; Check a case where the result is tested via slt.
+define void @f5(i8 *%src1, i8 *%src2, i64 *%dest) {
+; CHECK-LABEL: f5:
+; CHECK: clc 0(5,%r2), 0(%r3)
+; CHECK-NEXT: jl {{\..*}}
+; CHECK: br %r14
+entry:
+ %res = call i64 @memcmp(i8 *%src1, i8 *%src2, i64 5)
+ %cmp = icmp slt i64 %res, 0
+ br i1 %cmp, label %exit, label %store
+
+store:
+ store i64 0, i64 *%dest
+ br label %exit
+
+exit:
+ ret void
+}
+
+; Check a case where the result is tested for sgt.
+define void @f6(i8 *%src1, i8 *%src2, i64 *%dest) {
+; CHECK-LABEL: f6:
+; CHECK: clc 0(6,%r2), 0(%r3)
+; CHECK-NEXT: jh {{\..*}}
+; CHECK: br %r14
+entry:
+ %res = call i64 @memcmp(i8 *%src1, i8 *%src2, i64 6)
+ %cmp = icmp sgt i64 %res, 0
+ br i1 %cmp, label %exit, label %store
+
+store:
+ store i64 0, i64 *%dest
+ br label %exit
+
+exit:
+ ret void
+}
+
+; Check the upper end of the CLC range. Here the result is used both as
+; an integer and for branching.
+define i64 @f7(i8 *%src1, i8 *%src2, i64 *%dest) {
+; CHECK-LABEL: f7:
+; CHECK: clc 0(256,%r2), 0(%r3)
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: srl [[REG]], 28
+; CHECK: rll [[REG]], [[REG]], 31
+; CHECK: lgfr %r2, [[REG]]
+; CHECK: jl {{.L*}}
+; CHECK: br %r14
+entry:
+ %res = call i64 @memcmp(i8 *%src1, i8 *%src2, i64 256)
+ %cmp = icmp slt i64 %res, 0
+ br i1 %cmp, label %exit, label %store
+
+store:
+ store i64 0, i64 *%dest
+ br label %exit
+
+exit:
+ ret i64 %res
+}
+
+; 257 bytes is too big for a single CLC. For now expect a call instead.
+define i64 @f8(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f8:
+; CHECK: brasl %r14, memcmp at PLT
+; CHECK: br %r14
+ %res = call i64 @memcmp(i8 *%src1, i8 *%src2, i64 257)
+ ret i64 %res
+}
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