[llvm-commits] [llvm] r82470 - in /llvm/trunk: lib/Target/X86/X86InstrInfo.cpp lib/Target/X86/X86InstrSSE.td test/CodeGen/X86/remat-scalar-zero.ll
Dan Gohman
gohman at apple.com
Mon Sep 21 11:30:38 PDT 2009
Author: djg
Date: Mon Sep 21 13:30:38 2009
New Revision: 82470
URL: http://llvm.org/viewvc/llvm-project?rev=82470&view=rev
Log:
Add support for rematerializing FsFLD0SS and FsFLD0SD as constant-pool
loads in order to reduce register pressure.
Added:
llvm/trunk/test/CodeGen/X86/remat-scalar-zero.ll
Modified:
llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
llvm/trunk/lib/Target/X86/X86InstrSSE.td
Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.cpp?rev=82470&r1=82469&r2=82470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86InstrInfo.cpp Mon Sep 21 13:30:38 2009
@@ -2297,9 +2297,21 @@
unsigned Alignment = 0;
if (LoadMI->hasOneMemOperand())
Alignment = LoadMI->memoperands_begin()->getAlignment();
- else if (LoadMI->getOpcode() == X86::V_SET0 ||
- LoadMI->getOpcode() == X86::V_SETALLONES)
- Alignment = 16;
+ else
+ switch (LoadMI->getOpcode()) {
+ case X86::V_SET0:
+ case X86::V_SETALLONES:
+ Alignment = 16;
+ break;
+ case X86::FsFLD0SD:
+ Alignment = 8;
+ break;
+ case X86::FsFLD0SS:
+ Alignment = 4;
+ break;
+ default:
+ llvm_unreachable("Don't know how to fold this instruction!");
+ }
if (Ops.size() == 2 && Ops[0] == 0 && Ops[1] == 1) {
unsigned NewOpc = 0;
switch (MI->getOpcode()) {
@@ -2316,8 +2328,11 @@
return NULL;
SmallVector<MachineOperand,X86AddrNumOperands> MOs;
- if (LoadMI->getOpcode() == X86::V_SET0 ||
- LoadMI->getOpcode() == X86::V_SETALLONES) {
+ switch (LoadMI->getOpcode()) {
+ case X86::V_SET0:
+ case X86::V_SETALLONES:
+ case X86::FsFLD0SD:
+ case X86::FsFLD0SS: {
// Folding a V_SET0 or V_SETALLONES as a load, to ease register pressure.
// Create a constant-pool entry and operands to load from it.
@@ -2331,17 +2346,22 @@
// This doesn't work for several reasons.
// 1. GlobalBaseReg may have been spilled.
// 2. It may not be live at MI.
- return false;
+ return NULL;
}
- // Create a v4i32 constant-pool entry.
+ // Create a constant-pool entry.
MachineConstantPool &MCP = *MF.getConstantPool();
- const VectorType *Ty =
- VectorType::get(Type::getInt32Ty(MF.getFunction()->getContext()), 4);
- Constant *C = LoadMI->getOpcode() == X86::V_SET0 ?
- Constant::getNullValue(Ty) :
- Constant::getAllOnesValue(Ty);
- unsigned CPI = MCP.getConstantPoolIndex(C, 16);
+ const Type *Ty;
+ if (LoadMI->getOpcode() == X86::FsFLD0SS)
+ Ty = Type::getFloatTy(MF.getFunction()->getContext());
+ else if (LoadMI->getOpcode() == X86::FsFLD0SD)
+ Ty = Type::getDoubleTy(MF.getFunction()->getContext());
+ else
+ Ty = VectorType::get(Type::getInt32Ty(MF.getFunction()->getContext()), 4);
+ Constant *C = LoadMI->getOpcode() == X86::V_SETALLONES ?
+ Constant::getAllOnesValue(Ty) :
+ Constant::getNullValue(Ty);
+ unsigned CPI = MCP.getConstantPoolIndex(C, Alignment);
// Create operands to load from the constant pool entry.
MOs.push_back(MachineOperand::CreateReg(PICBase, false));
@@ -2349,11 +2369,15 @@
MOs.push_back(MachineOperand::CreateReg(0, false));
MOs.push_back(MachineOperand::CreateCPI(CPI, 0));
MOs.push_back(MachineOperand::CreateReg(0, false));
- } else {
+ break;
+ }
+ default: {
// Folding a normal load. Just copy the load's address operands.
unsigned NumOps = LoadMI->getDesc().getNumOperands();
for (unsigned i = NumOps - X86AddrNumOperands; i != NumOps; ++i)
MOs.push_back(LoadMI->getOperand(i));
+ break;
+ }
}
return foldMemoryOperandImpl(MF, MI, Ops[0], MOs, 0, Alignment);
}
Modified: llvm/trunk/lib/Target/X86/X86InstrSSE.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrSSE.td?rev=82470&r1=82469&r2=82470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrSSE.td (original)
+++ llvm/trunk/lib/Target/X86/X86InstrSSE.td Mon Sep 21 13:30:38 2009
@@ -472,7 +472,8 @@
// that start with 'Fs'.
// Alias instructions that map fld0 to pxor for sse.
-let isReMaterializable = 1, isAsCheapAsAMove = 1, isCodeGenOnly = 1 in
+let isReMaterializable = 1, isAsCheapAsAMove = 1, isCodeGenOnly = 1,
+ canFoldAsLoad = 1 in
def FsFLD0SS : I<0xEF, MRMInitReg, (outs FR32:$dst), (ins),
"pxor\t$dst, $dst", [(set FR32:$dst, fp32imm0)]>,
Requires<[HasSSE1]>, TB, OpSize;
@@ -1230,7 +1231,8 @@
// that start with 'Fs'.
// Alias instructions that map fld0 to pxor for sse.
-let isReMaterializable = 1, isAsCheapAsAMove = 1, isCodeGenOnly = 1 in
+let isReMaterializable = 1, isAsCheapAsAMove = 1, isCodeGenOnly = 1,
+ canFoldAsLoad = 1 in
def FsFLD0SD : I<0xEF, MRMInitReg, (outs FR64:$dst), (ins),
"pxor\t$dst, $dst", [(set FR64:$dst, fpimm0)]>,
Requires<[HasSSE2]>, TB, OpSize;
Added: llvm/trunk/test/CodeGen/X86/remat-scalar-zero.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/remat-scalar-zero.ll?rev=82470&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/remat-scalar-zero.ll (added)
+++ llvm/trunk/test/CodeGen/X86/remat-scalar-zero.ll Mon Sep 21 13:30:38 2009
@@ -0,0 +1,95 @@
+; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu > %t
+; RUN: not grep xor %t
+; RUN: not grep movap %t
+; RUN: grep {\\.zero} %t
+
+; Remat should be able to fold the zero constant into the div instructions
+; as a constant-pool load.
+
+define void @foo(double* nocapture %x, double* nocapture %y) nounwind {
+entry:
+ %tmp1 = load double* %x ; <double> [#uses=1]
+ %arrayidx4 = getelementptr inbounds double* %x, i64 1 ; <double*> [#uses=1]
+ %tmp5 = load double* %arrayidx4 ; <double> [#uses=1]
+ %arrayidx8 = getelementptr inbounds double* %x, i64 2 ; <double*> [#uses=1]
+ %tmp9 = load double* %arrayidx8 ; <double> [#uses=1]
+ %arrayidx12 = getelementptr inbounds double* %x, i64 3 ; <double*> [#uses=1]
+ %tmp13 = load double* %arrayidx12 ; <double> [#uses=1]
+ %arrayidx16 = getelementptr inbounds double* %x, i64 4 ; <double*> [#uses=1]
+ %tmp17 = load double* %arrayidx16 ; <double> [#uses=1]
+ %arrayidx20 = getelementptr inbounds double* %x, i64 5 ; <double*> [#uses=1]
+ %tmp21 = load double* %arrayidx20 ; <double> [#uses=1]
+ %arrayidx24 = getelementptr inbounds double* %x, i64 6 ; <double*> [#uses=1]
+ %tmp25 = load double* %arrayidx24 ; <double> [#uses=1]
+ %arrayidx28 = getelementptr inbounds double* %x, i64 7 ; <double*> [#uses=1]
+ %tmp29 = load double* %arrayidx28 ; <double> [#uses=1]
+ %arrayidx32 = getelementptr inbounds double* %x, i64 8 ; <double*> [#uses=1]
+ %tmp33 = load double* %arrayidx32 ; <double> [#uses=1]
+ %arrayidx36 = getelementptr inbounds double* %x, i64 9 ; <double*> [#uses=1]
+ %tmp37 = load double* %arrayidx36 ; <double> [#uses=1]
+ %arrayidx40 = getelementptr inbounds double* %x, i64 10 ; <double*> [#uses=1]
+ %tmp41 = load double* %arrayidx40 ; <double> [#uses=1]
+ %arrayidx44 = getelementptr inbounds double* %x, i64 11 ; <double*> [#uses=1]
+ %tmp45 = load double* %arrayidx44 ; <double> [#uses=1]
+ %arrayidx48 = getelementptr inbounds double* %x, i64 12 ; <double*> [#uses=1]
+ %tmp49 = load double* %arrayidx48 ; <double> [#uses=1]
+ %arrayidx52 = getelementptr inbounds double* %x, i64 13 ; <double*> [#uses=1]
+ %tmp53 = load double* %arrayidx52 ; <double> [#uses=1]
+ %arrayidx56 = getelementptr inbounds double* %x, i64 14 ; <double*> [#uses=1]
+ %tmp57 = load double* %arrayidx56 ; <double> [#uses=1]
+ %arrayidx60 = getelementptr inbounds double* %x, i64 15 ; <double*> [#uses=1]
+ %tmp61 = load double* %arrayidx60 ; <double> [#uses=1]
+ %arrayidx64 = getelementptr inbounds double* %x, i64 16 ; <double*> [#uses=1]
+ %tmp65 = load double* %arrayidx64 ; <double> [#uses=1]
+ %div = fdiv double %tmp1, 0.000000e+00 ; <double> [#uses=1]
+ store double %div, double* %y
+ %div70 = fdiv double %tmp5, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx72 = getelementptr inbounds double* %y, i64 1 ; <double*> [#uses=1]
+ store double %div70, double* %arrayidx72
+ %div74 = fdiv double %tmp9, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx76 = getelementptr inbounds double* %y, i64 2 ; <double*> [#uses=1]
+ store double %div74, double* %arrayidx76
+ %div78 = fdiv double %tmp13, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx80 = getelementptr inbounds double* %y, i64 3 ; <double*> [#uses=1]
+ store double %div78, double* %arrayidx80
+ %div82 = fdiv double %tmp17, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx84 = getelementptr inbounds double* %y, i64 4 ; <double*> [#uses=1]
+ store double %div82, double* %arrayidx84
+ %div86 = fdiv double %tmp21, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx88 = getelementptr inbounds double* %y, i64 5 ; <double*> [#uses=1]
+ store double %div86, double* %arrayidx88
+ %div90 = fdiv double %tmp25, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx92 = getelementptr inbounds double* %y, i64 6 ; <double*> [#uses=1]
+ store double %div90, double* %arrayidx92
+ %div94 = fdiv double %tmp29, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx96 = getelementptr inbounds double* %y, i64 7 ; <double*> [#uses=1]
+ store double %div94, double* %arrayidx96
+ %div98 = fdiv double %tmp33, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx100 = getelementptr inbounds double* %y, i64 8 ; <double*> [#uses=1]
+ store double %div98, double* %arrayidx100
+ %div102 = fdiv double %tmp37, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx104 = getelementptr inbounds double* %y, i64 9 ; <double*> [#uses=1]
+ store double %div102, double* %arrayidx104
+ %div106 = fdiv double %tmp41, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx108 = getelementptr inbounds double* %y, i64 10 ; <double*> [#uses=1]
+ store double %div106, double* %arrayidx108
+ %div110 = fdiv double %tmp45, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx112 = getelementptr inbounds double* %y, i64 11 ; <double*> [#uses=1]
+ store double %div110, double* %arrayidx112
+ %div114 = fdiv double %tmp49, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx116 = getelementptr inbounds double* %y, i64 12 ; <double*> [#uses=1]
+ store double %div114, double* %arrayidx116
+ %div118 = fdiv double %tmp53, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx120 = getelementptr inbounds double* %y, i64 13 ; <double*> [#uses=1]
+ store double %div118, double* %arrayidx120
+ %div122 = fdiv double %tmp57, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx124 = getelementptr inbounds double* %y, i64 14 ; <double*> [#uses=1]
+ store double %div122, double* %arrayidx124
+ %div126 = fdiv double %tmp61, 2.000000e-01 ; <double> [#uses=1]
+ %arrayidx128 = getelementptr inbounds double* %y, i64 15 ; <double*> [#uses=1]
+ store double %div126, double* %arrayidx128
+ %div130 = fdiv double %tmp65, 0.000000e+00 ; <double> [#uses=1]
+ %arrayidx132 = getelementptr inbounds double* %y, i64 16 ; <double*> [#uses=1]
+ store double %div130, double* %arrayidx132
+ ret void
+}
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