[llvm] r268539 - [AArch64] Use the reciprocal estimation machinery
Evandro Menezes via llvm-commits
llvm-commits at lists.llvm.org
Wed May 4 13:18:28 PDT 2016
Author: evandro
Date: Wed May 4 15:18:27 2016
New Revision: 268539
URL: http://llvm.org/viewvc/llvm-project?rev=268539&view=rev
Log:
[AArch64] Use the reciprocal estimation machinery
This patch adds support for estimating the square root, its reciprocal and
division or reciprocal using the combiner generic reciprocal machinery.
Added:
llvm/trunk/test/CodeGen/AArch64/recp-fastmath.ll
llvm/trunk/test/CodeGen/AArch64/sqrt-fastmath.ll
Modified:
llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.cpp
llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.h
llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.td
llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.cpp
llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.h
Modified: llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.cpp?rev=268539&r1=268538&r2=268539&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.cpp Wed May 4 15:18:27 2016
@@ -970,6 +970,8 @@ const char *AArch64TargetLowering::getTa
case AArch64ISD::ST4LANEpost: return "AArch64ISD::ST4LANEpost";
case AArch64ISD::SMULL: return "AArch64ISD::SMULL";
case AArch64ISD::UMULL: return "AArch64ISD::UMULL";
+ case AArch64ISD::FRSQRTE: return "AArch64ISD::FRSQRTE";
+ case AArch64ISD::FRECPE: return "AArch64ISD::FRECPE";
}
return nullptr;
}
@@ -4624,6 +4626,40 @@ bool AArch64TargetLowering::isFPImmLegal
// AArch64 Optimization Hooks
//===----------------------------------------------------------------------===//
+/// getEstimate - Return the appropriate estimate DAG for either the reciprocal
+/// or the reciprocal square root.
+static SDValue getEstimate(const AArch64Subtarget &ST,
+ const AArch64TargetLowering::DAGCombinerInfo &DCI, unsigned Opcode,
+ const SDValue &Operand, unsigned &ExtraSteps) {
+ if (!ST.hasNEON())
+ return SDValue();
+
+ EVT VT = Operand.getValueType();
+
+ std::string RecipOp;
+ RecipOp = Opcode == (AArch64ISD::FRECPE) ? "div": "sqrt";
+ RecipOp = ((VT.isVector()) ? "vec-": "") + RecipOp;
+ RecipOp += (VT.getScalarType() == MVT::f64) ? "d": "f";
+
+ TargetRecip Recips = DCI.DAG.getTarget().Options.Reciprocals;
+ if (!Recips.isEnabled(RecipOp))
+ return SDValue();
+
+ ExtraSteps = Recips.getRefinementSteps(RecipOp);
+ return DCI.DAG.getNode(Opcode, SDLoc(Operand), VT, Operand);
+}
+
+SDValue AArch64TargetLowering::getRecipEstimate(SDValue Operand,
+ DAGCombinerInfo &DCI, unsigned &ExtraSteps) const {
+ return getEstimate(*Subtarget, DCI, AArch64ISD::FRECPE, Operand, ExtraSteps);
+}
+
+SDValue AArch64TargetLowering::getRsqrtEstimate(SDValue Operand,
+ DAGCombinerInfo &DCI, unsigned &ExtraSteps, bool &UseOneConst) const {
+ UseOneConst = true;
+ return getEstimate(*Subtarget, DCI, AArch64ISD::FRSQRTE, Operand, ExtraSteps);
+}
+
//===----------------------------------------------------------------------===//
// AArch64 Inline Assembly Support
//===----------------------------------------------------------------------===//
Modified: llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.h?rev=268539&r1=268538&r2=268539&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.h (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64ISelLowering.h Wed May 4 15:18:27 2016
@@ -187,6 +187,10 @@ enum NodeType : unsigned {
SMULL,
UMULL,
+ // Reciprocal estimates.
+ FRECPE,
+ FRSQRTE,
+
// NEON Load/Store with post-increment base updates
LD2post = ISD::FIRST_TARGET_MEMORY_OPCODE,
LD3post,
@@ -511,6 +515,11 @@ private:
SDValue BuildSDIVPow2(SDNode *N, const APInt &Divisor, SelectionDAG &DAG,
std::vector<SDNode *> *Created) const override;
+ SDValue getRsqrtEstimate(SDValue Operand, DAGCombinerInfo &DCI,
+ unsigned &RefinementSteps,
+ bool &UseOneConstNR) const override;
+ SDValue getRecipEstimate(SDValue Operand, DAGCombinerInfo &DCI,
+ unsigned &RefinementSteps) const override;
unsigned combineRepeatedFPDivisors() const override;
ConstraintType getConstraintType(StringRef Constraint) const override;
Modified: llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.td?rev=268539&r1=268538&r2=268539&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.td (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.td Wed May 4 15:18:27 2016
@@ -283,6 +283,9 @@ def SDT_AArch64mull : SDTypeProfile<1, 2
def AArch64smull : SDNode<"AArch64ISD::SMULL", SDT_AArch64mull>;
def AArch64umull : SDNode<"AArch64ISD::UMULL", SDT_AArch64mull>;
+def AArch64frecpe : SDNode<"AArch64ISD::FRECPE", SDTFPUnaryOp>;
+def AArch64frsqrte : SDNode<"AArch64ISD::FRSQRTE", SDTFPUnaryOp>;
+
def AArch64saddv : SDNode<"AArch64ISD::SADDV", SDT_AArch64UnaryVec>;
def AArch64uaddv : SDNode<"AArch64ISD::UADDV", SDT_AArch64UnaryVec>;
def AArch64sminv : SDNode<"AArch64ISD::SMINV", SDT_AArch64UnaryVec>;
@@ -3401,6 +3404,19 @@ def : Pat<(f64 (int_aarch64_neon_frecpe
def : Pat<(v1f64 (int_aarch64_neon_frecpe (v1f64 FPR64:$Rn))),
(FRECPEv1i64 FPR64:$Rn)>;
+def : Pat<(f32 (AArch64frecpe (f32 FPR32:$Rn))),
+ (FRECPEv1i32 FPR32:$Rn)>;
+def : Pat<(v2f32 (AArch64frecpe (v2f32 V64:$Rn))),
+ (FRECPEv2f32 V64:$Rn)>;
+def : Pat<(v4f32 (AArch64frecpe (v4f32 FPR128:$Rn))),
+ (FRECPEv4f32 FPR128:$Rn)>;
+def : Pat<(f64 (AArch64frecpe (f64 FPR64:$Rn))),
+ (FRECPEv1i64 FPR64:$Rn)>;
+def : Pat<(v1f64 (AArch64frecpe (v1f64 FPR64:$Rn))),
+ (FRECPEv1i64 FPR64:$Rn)>;
+def : Pat<(v2f64 (AArch64frecpe (v2f64 FPR128:$Rn))),
+ (FRECPEv2f64 FPR128:$Rn)>;
+
def : Pat<(f32 (int_aarch64_neon_frecpx (f32 FPR32:$Rn))),
(FRECPXv1i32 FPR32:$Rn)>;
def : Pat<(f64 (int_aarch64_neon_frecpx (f64 FPR64:$Rn))),
@@ -3413,6 +3429,19 @@ def : Pat<(f64 (int_aarch64_neon_frsqrte
def : Pat<(v1f64 (int_aarch64_neon_frsqrte (v1f64 FPR64:$Rn))),
(FRSQRTEv1i64 FPR64:$Rn)>;
+def : Pat<(f32 (AArch64frsqrte (f32 FPR32:$Rn))),
+ (FRSQRTEv1i32 FPR32:$Rn)>;
+def : Pat<(v2f32 (AArch64frsqrte (v2f32 V64:$Rn))),
+ (FRSQRTEv2f32 V64:$Rn)>;
+def : Pat<(v4f32 (AArch64frsqrte (v4f32 FPR128:$Rn))),
+ (FRSQRTEv4f32 FPR128:$Rn)>;
+def : Pat<(f64 (AArch64frsqrte (f64 FPR64:$Rn))),
+ (FRSQRTEv1i64 FPR64:$Rn)>;
+def : Pat<(v1f64 (AArch64frsqrte (v1f64 FPR64:$Rn))),
+ (FRSQRTEv1i64 FPR64:$Rn)>;
+def : Pat<(v2f64 (AArch64frsqrte (v2f64 FPR128:$Rn))),
+ (FRSQRTEv2f64 FPR128:$Rn)>;
+
// If an integer is about to be converted to a floating point value,
// just load it on the floating point unit.
// Here are the patterns for 8 and 16-bits to float.
Modified: llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.cpp?rev=268539&r1=268538&r2=268539&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.cpp Wed May 4 15:18:27 2016
@@ -136,6 +136,30 @@ static std::string computeDataLayout(con
return "E-m:e-i64:64-i128:128-n32:64-S128";
}
+// Helper function to set up the defaults for reciprocals.
+static void initReciprocals(AArch64TargetMachine& TM, AArch64Subtarget& ST)
+{
+ // For the estimates, convergence is quadratic, so essentially the number of
+ // digits is doubled after each iteration. ARMv8, the minimum architected
+ // accuracy of the initial estimate is 2^-8. Therefore, the number of extra
+ // steps to refine the result for float (23 mantissa bits) and for double
+ // (52 mantissa bits) are 2 and 3, respectively.
+ unsigned ExtraStepsF = 2,
+ ExtraStepsD = ExtraStepsF + 1;
+ // FIXME: Enable x^-1/2 only for Exynos M1 at the moment.
+ bool UseRsqrt = ST.isExynosM1();
+
+ TM.Options.Reciprocals.setDefaults("sqrtf", UseRsqrt, ExtraStepsF);
+ TM.Options.Reciprocals.setDefaults("sqrtd", UseRsqrt, ExtraStepsD);
+ TM.Options.Reciprocals.setDefaults("vec-sqrtf", UseRsqrt, ExtraStepsF);
+ TM.Options.Reciprocals.setDefaults("vec-sqrtd", UseRsqrt, ExtraStepsD);
+
+ TM.Options.Reciprocals.setDefaults("divf", false, ExtraStepsF);
+ TM.Options.Reciprocals.setDefaults("divd", false, ExtraStepsD);
+ TM.Options.Reciprocals.setDefaults("vec-divf", false, ExtraStepsF);
+ TM.Options.Reciprocals.setDefaults("vec-divd", false, ExtraStepsD);
+}
+
/// TargetMachine ctor - Create an AArch64 architecture model.
///
AArch64TargetMachine::AArch64TargetMachine(const Target &T, const Triple &TT,
@@ -149,7 +173,8 @@ AArch64TargetMachine::AArch64TargetMachi
: LLVMTargetMachine(T, computeDataLayout(TT, LittleEndian), TT, CPU, FS,
Options, RM, CM, OL),
TLOF(createTLOF(getTargetTriple())),
- isLittle(LittleEndian) {
+ Subtarget(TT, CPU, FS, *this, LittleEndian) {
+ initReciprocals(*this, Subtarget);
initAsmInfo();
}
@@ -189,7 +214,7 @@ AArch64TargetMachine::getSubtargetImpl(c
// function that reside in TargetOptions.
resetTargetOptions(F);
I = llvm::make_unique<AArch64Subtarget>(TargetTriple, CPU, FS, *this,
- isLittle);
+ Subtarget.isLittleEndian());
#ifndef LLVM_BUILD_GLOBAL_ISEL
GISelAccessor *GISel = new GISelAccessor();
#else
Modified: llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.h?rev=268539&r1=268538&r2=268539&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.h (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64TargetMachine.h Wed May 4 15:18:27 2016
@@ -46,7 +46,7 @@ public:
}
private:
- bool isLittle;
+ AArch64Subtarget Subtarget;
};
// AArch64leTargetMachine - AArch64 little endian target machine.
Added: llvm/trunk/test/CodeGen/AArch64/recp-fastmath.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/recp-fastmath.ll?rev=268539&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/recp-fastmath.ll (added)
+++ llvm/trunk/test/CodeGen/AArch64/recp-fastmath.ll Wed May 4 15:18:27 2016
@@ -0,0 +1,79 @@
+; RUN: llc < %s -mtriple=aarch64 -mattr=neon -recip=!div,!vec-div | FileCheck %s --check-prefix=FAULT
+; RUN: llc < %s -mtriple=aarch64 -mattr=neon -recip=div,vec-div | FileCheck %s
+
+define float @frecp(float %x) #0 {
+ %div = fdiv fast float 1.0, %x
+ ret float %div
+
+; FAULT-LABEL: frecp:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fmov
+; FAULT-NEXT: fdiv
+
+; CHECK-LABEL: frecp:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: frecpe
+; CHECK-NEXT: fmov
+}
+
+define <2 x float> @f2recp(<2 x float> %x) #0 {
+ %div = fdiv fast <2 x float> <float 1.0, float 1.0>, %x
+ ret <2 x float> %div
+
+; FAULT-LABEL: f2recp:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fmov
+; FAULT-NEXT: fdiv
+
+; CHECK-LABEL: f2recp:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: frecpe
+}
+
+define <4 x float> @f4recp(<4 x float> %x) #0 {
+ %div = fdiv fast <4 x float> <float 1.0, float 1.0, float 1.0, float 1.0>, %x
+ ret <4 x float> %div
+
+; FAULT-LABEL: f4recp:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fmov
+; FAULT-NEXT: fdiv
+
+; CHECK-LABEL: f4recp:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: frecpe
+}
+
+define double @drecp(double %x) #0 {
+ %div = fdiv fast double 1.0, %x
+ ret double %div
+
+; FAULT-LABEL: drecp:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fmov
+; FAULT-NEXT: fdiv
+
+; CHECK-LABEL: drecp:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: frecpe
+; CHECK-NEXT: fmov
+}
+
+define <2 x double> @d2recp(<2 x double> %x) #0 {
+ %div = fdiv fast <2 x double> <double 1.0, double 1.0>, %x
+ ret <2 x double> %div
+
+; FAULT-LABEL: d2recp:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fmov
+; FAULT-NEXT: fdiv
+
+; CHECK-LABEL: d2recp:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: frecpe
+}
+
+attributes #0 = { nounwind "unsafe-fp-math"="true" }
Added: llvm/trunk/test/CodeGen/AArch64/sqrt-fastmath.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/sqrt-fastmath.ll?rev=268539&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/sqrt-fastmath.ll (added)
+++ llvm/trunk/test/CodeGen/AArch64/sqrt-fastmath.ll Wed May 4 15:18:27 2016
@@ -0,0 +1,158 @@
+; RUN: llc < %s -mtriple=aarch64 -mattr=neon -recip=!sqrt,!vec-sqrt | FileCheck %s --check-prefix=FAULT
+; RUN: llc < %s -mtriple=aarch64 -mattr=neon -recip=sqrt,vec-sqrt | FileCheck %s
+
+declare float @llvm.sqrt.f32(float) #1
+declare double @llvm.sqrt.f64(double) #1
+declare <2 x float> @llvm.sqrt.v2f32(<2 x float>) #1
+declare <4 x float> @llvm.sqrt.v4f32(<4 x float>) #1
+declare <2 x double> @llvm.sqrt.v2f64(<2 x double>) #1
+
+define float @fsqrt(float %a) #0 {
+ %1 = tail call fast float @llvm.sqrt.f32(float %a)
+ ret float %1
+
+; FAULT-LABEL: fsqrt:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fsqrt
+
+; CHECK-LABEL: fsqrt:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: frsqrte
+}
+
+define <2 x float> @f2sqrt(<2 x float> %a) #0 {
+ %1 = tail call fast <2 x float> @llvm.sqrt.v2f32(<2 x float> %a) #2
+ ret <2 x float> %1
+
+; FAULT-LABEL: f2sqrt:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fsqrt
+
+; CHECK-LABEL: f2sqrt:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: mov
+; CHECK-NEXT: frsqrte
+}
+
+define <4 x float> @f4sqrt(<4 x float> %a) #0 {
+ %1 = tail call fast <4 x float> @llvm.sqrt.v4f32(<4 x float> %a) #2
+ ret <4 x float> %1
+
+; FAULT-LABEL: f4sqrt:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fsqrt
+
+; CHECK-LABEL: f4sqrt:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: mov
+; CHECK-NEXT: frsqrte
+}
+
+define double @dsqrt(double %a) #0 {
+ %1 = tail call fast double @llvm.sqrt.f64(double %a)
+ ret double %1
+
+; FAULT-LABEL: dsqrt:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fsqrt
+
+; CHECK-LABEL: dsqrt:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: frsqrte
+}
+
+define <2 x double> @d2sqrt(<2 x double> %a) #0 {
+ %1 = tail call fast <2 x double> @llvm.sqrt.v2f64(<2 x double> %a) #2
+ ret <2 x double> %1
+
+; FAULT-LABEL: d2sqrt:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fsqrt
+
+; CHECK-LABEL: d2sqrt:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: mov
+; CHECK-NEXT: frsqrte
+}
+
+define float @frsqrt(float %a) #0 {
+ %1 = tail call fast float @llvm.sqrt.f32(float %a)
+ %2 = fdiv fast float 1.000000e+00, %1
+ ret float %2
+
+; FAULT-LABEL: frsqrt:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fsqrt
+
+; CHECK-LABEL: frsqrt:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: frsqrte
+}
+
+define <2 x float> @f2rsqrt(<2 x float> %a) #0 {
+ %1 = tail call fast <2 x float> @llvm.sqrt.v2f32(<2 x float> %a) #2
+ %2 = fdiv fast <2 x float> <float 1.000000e+00, float 1.000000e+00>, %1
+ ret <2 x float> %2
+
+; FAULT-LABEL: f2rsqrt:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fsqrt
+
+; CHECK-LABEL: f2rsqrt:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: frsqrte
+}
+
+define <4 x float> @f4rsqrt(<4 x float> %a) #0 {
+ %1 = tail call fast <4 x float> @llvm.sqrt.v4f32(<4 x float> %a) #2
+ %2 = fdiv fast <4 x float> <float 1.000000e+00, float 1.000000e+00, float 1.000000e+00, float 1.000000e+00>, %1
+ ret <4 x float> %2
+
+; FAULT-LABEL: f4rsqrt:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fsqrt
+
+; CHECK-LABEL: f4rsqrt:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: frsqrte
+}
+
+define double @drsqrt(double %a) #0 {
+ %1 = tail call fast double @llvm.sqrt.f64(double %a)
+ %2 = fdiv fast double 1.000000e+00, %1
+ ret double %2
+
+; FAULT-LABEL: drsqrt:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fsqrt
+
+; CHECK-LABEL: drsqrt:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: frsqrte
+}
+
+define <2 x double> @d2rsqrt(<2 x double> %a) #0 {
+ %1 = tail call fast <2 x double> @llvm.sqrt.v2f64(<2 x double> %a) #2
+ %2 = fdiv fast <2 x double> <double 1.000000e+00, double 1.000000e+00>, %1
+ ret <2 x double> %2
+
+; FAULT-LABEL: d2rsqrt:
+; FAULT-NEXT: BB#0
+; FAULT-NEXT: fsqrt
+
+; CHECK-LABEL: d2rsqrt:
+; CHECK-NEXT: BB#0
+; CHECK-NEXT: fmov
+; CHECK-NEXT: frsqrte
+}
+
+attributes #0 = { nounwind "unsafe-fp-math"="true" }
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