[llvm] r207127 - [X86] Add support for Read Time Stamp Counter x86 builtin intrinsics.
Andrea Di Biagio
Andrea_DiBiagio at sn.scee.net
Thu Apr 24 10:18:27 PDT 2014
Author: adibiagio
Date: Thu Apr 24 12:18:27 2014
New Revision: 207127
URL: http://llvm.org/viewvc/llvm-project?rev=207127&view=rev
Log:
[X86] Add support for Read Time Stamp Counter x86 builtin intrinsics.
This patch:
- Adds two new X86 builtin intrinsics ('int_x86_rdtsc' and
'int_x86_rdtscp') as GCCBuiltin intrinsics;
- Teaches the backend how to lower the two new builtins;
- Introduces a common function to lower READCYCLECOUNTER dag nodes
and the two new rdtsc/rdtscp intrinsics;
- Improves (and extends) the existing x86 test 'rdtsc.ll'; now test 'rdtsc.ll'
correctly verifies that both READCYCLECOUNTER and the two new intrinsics
work fine for both 64bit and 32bit Subtargets.
Modified:
llvm/trunk/include/llvm/IR/IntrinsicsX86.td
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/lib/Target/X86/X86ISelLowering.h
llvm/trunk/lib/Target/X86/X86InstrInfo.td
llvm/trunk/lib/Target/X86/X86InstrSystem.td
llvm/trunk/test/CodeGen/X86/rdtsc.ll
Modified: llvm/trunk/include/llvm/IR/IntrinsicsX86.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/IntrinsicsX86.td?rev=207127&r1=207126&r2=207127&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/IntrinsicsX86.td (original)
+++ llvm/trunk/include/llvm/IR/IntrinsicsX86.td Thu Apr 24 12:18:27 2014
@@ -18,6 +18,15 @@ let TargetPrefix = "x86" in { // All in
}
//===----------------------------------------------------------------------===//
+// Read Time Stamp Counter.
+let TargetPrefix = "x86" in {
+ def int_x86_rdtsc : GCCBuiltin<"__builtin_ia32_rdtsc">,
+ Intrinsic<[llvm_i64_ty], [], []>;
+ def int_x86_rdtscp : GCCBuiltin<"__builtin_ia32_rdtscp">,
+ Intrinsic<[llvm_i64_ty], [llvm_ptr_ty], [IntrReadWriteArgMem]>;
+}
+
+//===----------------------------------------------------------------------===//
// 3DNow!
let TargetPrefix = "x86" in {
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=207127&r1=207126&r2=207127&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Thu Apr 24 12:18:27 2014
@@ -1472,6 +1472,8 @@ void X86TargetLowering::resetOperationAc
setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
setOperationAction(ISD::INTRINSIC_W_CHAIN, MVT::Other, Custom);
setOperationAction(ISD::INTRINSIC_VOID, MVT::Other, Custom);
+ if (!Subtarget->is64Bit())
+ setOperationAction(ISD::INTRINSIC_W_CHAIN, MVT::i64, Custom);
// Only custom-lower 64-bit SADDO and friends on 64-bit because we don't
// handle type legalization for these operations here.
@@ -12261,6 +12263,71 @@ static SDValue getMScatterNode(unsigned
return SDValue(Res, 1);
}
+// getReadTimeStampCounter - Handles the lowering of builtin intrinsics that
+// read the time stamp counter (x86_rdtsc and x86_rdtscp). This function is
+// also used to custom lower READCYCLECOUNTER nodes.
+static void getReadTimeStampCounter(SDNode *N, SDLoc DL, unsigned Opcode,
+ SelectionDAG &DAG, const X86Subtarget *Subtarget,
+ SmallVectorImpl<SDValue> &Results) {
+ SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue);
+ SDValue TheChain = N->getOperand(0);
+ SDValue rd = DAG.getNode(Opcode, DL, Tys, &TheChain, 1);
+ SDValue LO, HI;
+
+ // The processor's time-stamp counter (a 64-bit MSR) is stored into the
+ // EDX:EAX registers. EDX is loaded with the high-order 32 bits of the MSR
+ // and the EAX register is loaded with the low-order 32 bits.
+ if (Subtarget->is64Bit()) {
+ LO = DAG.getCopyFromReg(rd, DL, X86::RAX, MVT::i64, rd.getValue(1));
+ HI = DAG.getCopyFromReg(LO.getValue(1), DL, X86::RDX, MVT::i64,
+ LO.getValue(2));
+ } else {
+ LO = DAG.getCopyFromReg(rd, DL, X86::EAX, MVT::i32, rd.getValue(1));
+ HI = DAG.getCopyFromReg(LO.getValue(1), DL, X86::EDX, MVT::i32,
+ LO.getValue(2));
+ }
+ SDValue Chain = HI.getValue(1);
+
+ if (Opcode == X86ISD::RDTSCP_DAG) {
+ assert(N->getNumOperands() == 3 && "Unexpected number of operands!");
+
+ // Instruction RDTSCP loads the IA32:TSC_AUX_MSR (address C000_0103H) into
+ // the ECX register. Add 'ecx' explicitly to the chain.
+ SDValue ecx = DAG.getCopyFromReg(Chain, DL, X86::ECX, MVT::i32,
+ HI.getValue(2));
+ // Explicitly store the content of ECX at the location passed in input
+ // to the 'rdtscp' intrinsic.
+ Chain = DAG.getStore(ecx.getValue(1), DL, ecx, N->getOperand(2),
+ MachinePointerInfo(), false, false, 0);
+ }
+
+ if (Subtarget->is64Bit()) {
+ // The EDX register is loaded with the high-order 32 bits of the MSR, and
+ // the EAX register is loaded with the low-order 32 bits.
+ SDValue Tmp = DAG.getNode(ISD::SHL, DL, MVT::i64, HI,
+ DAG.getConstant(32, MVT::i8));
+ Results.push_back(DAG.getNode(ISD::OR, DL, MVT::i64, LO, Tmp));
+ Results.push_back(Chain);
+ return;
+ }
+
+ // Use a buildpair to merge the two 32-bit values into a 64-bit one.
+ SDValue Ops[] = { LO, HI };
+ SDValue Pair = DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, Ops,
+ array_lengthof(Ops));
+ Results.push_back(Pair);
+ Results.push_back(Chain);
+}
+
+static SDValue LowerREADCYCLECOUNTER(SDValue Op, const X86Subtarget *Subtarget,
+ SelectionDAG &DAG) {
+ SmallVector<SDValue, 2> Results;
+ SDLoc DL(Op);
+ getReadTimeStampCounter(Op.getNode(), DL, X86ISD::RDTSC_DAG, DAG, Subtarget,
+ Results);
+ return DAG.getMergeValues(&Results[0], Results.size(), DL);
+}
+
static SDValue LowerINTRINSIC_W_CHAIN(SDValue Op, const X86Subtarget *Subtarget,
SelectionDAG &DAG) {
SDLoc dl(Op);
@@ -12435,6 +12502,22 @@ static SDValue LowerINTRINSIC_W_CHAIN(SD
SDValue Scale = Op.getOperand(6);
return getMScatterNode(Opc, Op, DAG, Src, Mask, Base, Index, Scale, Chain);
}
+ // Read Time Stamp Counter (RDTSC).
+ case Intrinsic::x86_rdtsc:
+ // Read Time Stamp Counter and Processor ID (RDTSCP).
+ case Intrinsic::x86_rdtscp: {
+ unsigned Opc;
+ switch (IntNo) {
+ default: llvm_unreachable("Impossible intrinsic"); // Can't reach here.
+ case Intrinsic::x86_rdtsc:
+ Opc = X86ISD::RDTSC_DAG; break;
+ case Intrinsic::x86_rdtscp:
+ Opc = X86ISD::RDTSCP_DAG; break;
+ }
+ SmallVector<SDValue, 2> Results;
+ getReadTimeStampCounter(Op.getNode(), dl, Opc, DAG, Subtarget, Results);
+ return DAG.getMergeValues(&Results[0], Results.size(), dl);
+ }
// XTEST intrinsics.
case Intrinsic::x86_xtest: {
SDVTList VTs = DAG.getVTList(Op->getValueType(0), MVT::Other);
@@ -13805,25 +13888,6 @@ static SDValue LowerCMP_SWAP(SDValue Op,
return cpOut;
}
-static SDValue LowerREADCYCLECOUNTER(SDValue Op, const X86Subtarget *Subtarget,
- SelectionDAG &DAG) {
- assert(Subtarget->is64Bit() && "Result not type legalized?");
- SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue);
- SDValue TheChain = Op.getOperand(0);
- SDLoc dl(Op);
- SDValue rd = DAG.getNode(X86ISD::RDTSC_DAG, dl, Tys, &TheChain, 1);
- SDValue rax = DAG.getCopyFromReg(rd, dl, X86::RAX, MVT::i64, rd.getValue(1));
- SDValue rdx = DAG.getCopyFromReg(rax.getValue(1), dl, X86::RDX, MVT::i64,
- rax.getValue(2));
- SDValue Tmp = DAG.getNode(ISD::SHL, dl, MVT::i64, rdx,
- DAG.getConstant(32, MVT::i8));
- SDValue Ops[] = {
- DAG.getNode(ISD::OR, dl, MVT::i64, rax, Tmp),
- rdx.getValue(1)
- };
- return DAG.getMergeValues(Ops, array_lengthof(Ops), dl);
-}
-
static SDValue LowerBITCAST(SDValue Op, const X86Subtarget *Subtarget,
SelectionDAG &DAG) {
MVT SrcVT = Op.getOperand(0).getSimpleValueType();
@@ -14158,20 +14222,22 @@ void X86TargetLowering::ReplaceNodeResul
Results.push_back(V);
return;
}
+ case ISD::INTRINSIC_W_CHAIN: {
+ unsigned IntNo = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
+ switch (IntNo) {
+ default : llvm_unreachable("Do not know how to custom type "
+ "legalize this intrinsic operation!");
+ case Intrinsic::x86_rdtsc:
+ return getReadTimeStampCounter(N, dl, X86ISD::RDTSC_DAG, DAG, Subtarget,
+ Results);
+ case Intrinsic::x86_rdtscp:
+ return getReadTimeStampCounter(N, dl, X86ISD::RDTSCP_DAG, DAG, Subtarget,
+ Results);
+ }
+ }
case ISD::READCYCLECOUNTER: {
- SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue);
- SDValue TheChain = N->getOperand(0);
- SDValue rd = DAG.getNode(X86ISD::RDTSC_DAG, dl, Tys, &TheChain, 1);
- SDValue eax = DAG.getCopyFromReg(rd, dl, X86::EAX, MVT::i32,
- rd.getValue(1));
- SDValue edx = DAG.getCopyFromReg(eax.getValue(1), dl, X86::EDX, MVT::i32,
- eax.getValue(2));
- // Use a buildpair to merge the two 32-bit values into a 64-bit one.
- SDValue Ops[] = { eax, edx };
- Results.push_back(DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Ops,
- array_lengthof(Ops)));
- Results.push_back(edx.getValue(1));
- return;
+ return getReadTimeStampCounter(N, dl, X86ISD::RDTSC_DAG, DAG, Subtarget,
+ Results);
}
case ISD::ATOMIC_CMP_SWAP: {
EVT T = N->getValueType(0);
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.h?rev=207127&r1=207126&r2=207127&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.h (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.h Thu Apr 24 12:18:27 2014
@@ -83,6 +83,9 @@ namespace llvm {
/// readcyclecounter
RDTSC_DAG,
+ /// X86 Read Time-Stamp Counter and Processor ID.
+ RDTSCP_DAG,
+
/// X86 compare and logical compare instructions.
CMP, COMI, UCOMI,
Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.td?rev=207127&r1=207126&r2=207127&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrInfo.td (original)
+++ llvm/trunk/lib/Target/X86/X86InstrInfo.td Thu Apr 24 12:18:27 2014
@@ -206,6 +206,8 @@ def X86rep_movs: SDNode<"X86ISD::REP_MOV
def X86rdtsc : SDNode<"X86ISD::RDTSC_DAG", SDTX86Void,
[SDNPHasChain, SDNPOutGlue, SDNPSideEffect]>;
+def X86rdtscp : SDNode<"X86ISD::RDTSCP_DAG", SDTX86Void,
+ [SDNPHasChain, SDNPOutGlue, SDNPSideEffect]>;
def X86Wrapper : SDNode<"X86ISD::Wrapper", SDTX86Wrapper>;
def X86WrapperRIP : SDNode<"X86ISD::WrapperRIP", SDTX86Wrapper>;
Modified: llvm/trunk/lib/Target/X86/X86InstrSystem.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrSystem.td?rev=207127&r1=207126&r2=207127&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrSystem.td (original)
+++ llvm/trunk/lib/Target/X86/X86InstrSystem.td Thu Apr 24 12:18:27 2014
@@ -19,7 +19,7 @@ let Defs = [RAX, RDX] in
TB;
let Defs = [RAX, RCX, RDX] in
- def RDTSCP : I<0x01, MRM_F9, (outs), (ins), "rdtscp", []>, TB;
+ def RDTSCP : I<0x01, MRM_F9, (outs), (ins), "rdtscp", [(X86rdtscp)]>, TB;
// CPU flow control instructions
Modified: llvm/trunk/test/CodeGen/X86/rdtsc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/rdtsc.ll?rev=207127&r1=207126&r2=207127&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/rdtsc.ll (original)
+++ llvm/trunk/test/CodeGen/X86/rdtsc.ll Thu Apr 24 12:18:27 2014
@@ -1,8 +1,49 @@
-; RUN: llc < %s -march=x86 | grep rdtsc
-; RUN: llc < %s -march=x86-64 | grep rdtsc
-declare i64 @llvm.readcyclecounter()
+; RUN: llc < %s -march=x86-64 -mcpu=generic | FileCheck %s
+; RUN: llc < %s -march=x86 -mcpu=generic | FileCheck %s --check-prefix=CHECK --check-prefix=X86
+
+; Verify that we correctly lower ISD::READCYCLECOUNTER.
+
+
+define i64 @test_builtin_readcyclecounter() {
+ %1 = tail call i64 @llvm.readcyclecounter()
+ ret i64 %1
+}
+; CHECK-LABEL: test_builtin_readcyclecounter
+; CHECK: rdtsc
+; X86-NOT: shlq
+; X86-NOT: or
+; CHECK-NOT: mov
+; CHECK: ret
+
+
+; Verify that we correctly lower the Read Cycle Counter GCC x86 builtins
+; (i.e. RDTSC and RDTSCP).
-define i64 @foo() {
- %tmp.1 = call i64 @llvm.readcyclecounter( ) ; <i64> [#uses=1]
- ret i64 %tmp.1
+define i64 @test_builtin_rdtsc() {
+ %1 = tail call i64 @llvm.x86.rdtsc()
+ ret i64 %1
}
+; CHECK-LABEL: test_builtin_rdtsc
+; CHECK: rdtsc
+; X86-NOT: shlq
+; X86-NOT: or
+; CHECK-NOT: mov
+; CHECK: ret
+
+
+define i64 @test_builtin_rdtscp(i8* %A) {
+ %1 = tail call i64 @llvm.x86.rdtscp(i8* %A)
+ ret i64 %1
+}
+; CHECK-LABEL: test_builtin_rdtscp
+; CHECK: rdtscp
+; X86-NOT: shlq
+; CHECK: movl %ecx, (%{{[a-z]+}})
+; X86-NOT: shlq
+; CHECK: ret
+
+
+declare i64 @llvm.readcyclecounter()
+declare i64 @llvm.x86.rdtscp(i8*)
+declare i64 @llvm.x86.rdtsc()
+
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