Mesa (master): radeon/llvm: Rework how immediate operands are handled with SI
Tom Stellard
tstellar at kemper.freedesktop.org
Fri Aug 31 17:42:50 UTC 2012
Module: Mesa
Branch: master
Commit: 022f6d88616bf5ea3903c5056d6147e9cf356aa9
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=022f6d88616bf5ea3903c5056d6147e9cf356aa9
Author: Tom Stellard <thomas.stellard at amd.com>
Date: Fri Aug 31 11:29:49 2012 -0400
radeon/llvm: Rework how immediate operands are handled with SI
Immediate operands were previously handled in the CodeEmitter, but that
code was buggy and very confusing. This commit adds a pass that simplifies
the handling of immediate operands by spliting the loading of the
immediate into a sperate insruction that is bundled with the original.
---
src/gallium/drivers/radeon/AMDGPU.h | 1 +
src/gallium/drivers/radeon/AMDGPUAsmPrinter.cpp | 6 +-
src/gallium/drivers/radeon/AMDGPUTargetMachine.cpp | 2 +
.../radeon/MCTargetDesc/SIMCCodeEmitter.cpp | 39 +++-----
src/gallium/drivers/radeon/Makefile.sources | 1 +
src/gallium/drivers/radeon/SIGenRegisterInfo.pl | 1 +
src/gallium/drivers/radeon/SIISelLowering.h | 2 +
src/gallium/drivers/radeon/SIInstrInfo.td | 10 --
src/gallium/drivers/radeon/SIInstructions.td | 27 ++++--
.../drivers/radeon/SILowerLiteralConstants.cpp | 105 ++++++++++++++++++++
10 files changed, 150 insertions(+), 44 deletions(-)
diff --git a/src/gallium/drivers/radeon/AMDGPU.h b/src/gallium/drivers/radeon/AMDGPU.h
index 514adb6..ab6871c 100644
--- a/src/gallium/drivers/radeon/AMDGPU.h
+++ b/src/gallium/drivers/radeon/AMDGPU.h
@@ -26,6 +26,7 @@ FunctionPass *createR600ExpandSpecialInstrsPass(TargetMachine &tm);
// SI Passes
FunctionPass *createSIAssignInterpRegsPass(TargetMachine &tm);
FunctionPass *createSICodeEmitterPass(formatted_raw_ostream &OS);
+FunctionPass *createSILowerLiteralConstantsPass(TargetMachine &tm);
// Passes common to R600 and SI
FunctionPass *createAMDGPUConvertToISAPass(TargetMachine &tm);
diff --git a/src/gallium/drivers/radeon/AMDGPUAsmPrinter.cpp b/src/gallium/drivers/radeon/AMDGPUAsmPrinter.cpp
index bf3d89c..2d6c86d 100644
--- a/src/gallium/drivers/radeon/AMDGPUAsmPrinter.cpp
+++ b/src/gallium/drivers/radeon/AMDGPUAsmPrinter.cpp
@@ -81,9 +81,13 @@ void AMDGPUAsmPrinter::EmitProgramInfo(MachineFunction &MF) {
VCCUsed = true;
continue;
}
- if (reg == AMDGPU::EXEC) {
+ switch (reg) {
+ default: break;
+ case AMDGPU::EXEC:
+ case AMDGPU::SI_LITERAL_CONSTANT:
continue;
}
+
if (AMDGPU::SReg_32RegClass.contains(reg)) {
isSGPR = true;
width = 1;
diff --git a/src/gallium/drivers/radeon/AMDGPUTargetMachine.cpp b/src/gallium/drivers/radeon/AMDGPUTargetMachine.cpp
index 8de7bb7..2d1ca06 100644
--- a/src/gallium/drivers/radeon/AMDGPUTargetMachine.cpp
+++ b/src/gallium/drivers/radeon/AMDGPUTargetMachine.cpp
@@ -137,6 +137,8 @@ bool AMDGPUPassConfig::addPreEmitPass() {
if (ST.device()->getGeneration() <= AMDGPUDeviceInfo::HD6XXX) {
PM->add(createR600ExpandSpecialInstrsPass(*TM));
addPass(FinalizeMachineBundlesID);
+ } else {
+ PM->add(createSILowerLiteralConstantsPass(*TM));
}
return false;
diff --git a/src/gallium/drivers/radeon/MCTargetDesc/SIMCCodeEmitter.cpp b/src/gallium/drivers/radeon/MCTargetDesc/SIMCCodeEmitter.cpp
index 5569cf6..c2b5e47 100644
--- a/src/gallium/drivers/radeon/MCTargetDesc/SIMCCodeEmitter.cpp
+++ b/src/gallium/drivers/radeon/MCTargetDesc/SIMCCodeEmitter.cpp
@@ -22,11 +22,9 @@
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/Support/raw_ostream.h"
-#define LITERAL_REG 255
#define VGPR_BIT(src_idx) (1ULL << (9 * src_idx - 1))
#define SI_INSTR_FLAGS_ENCODING_MASK 0xf
-
// These must be kept in sync with SIInstructions.td and also the
// InstrEncodingInfo array in SIInstrInfo.cpp.
//
@@ -91,11 +89,6 @@ public:
virtual unsigned GPR4AlignEncode(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixup) const;
- /// i32LiteralEncode - Encode an i32 literal this is used as an operand
- /// for an instruction in place of a register.
- virtual uint64_t i32LiteralEncode(const MCInst &MI, unsigned OpNo,
- SmallVectorImpl<MCFixup> &Fixup) const;
-
/// SMRDmemriEncode - Encoding for SMRD indexed loads
virtual uint32_t SMRDmemriEncode(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixup) const;
@@ -147,7 +140,12 @@ uint64_t SIMCCodeEmitter::getMachineOpValue(const MCInst &MI,
} else if (MO.isFPImm()) {
// XXX: Not all instructions can use inline literals
// XXX: We should make sure this is a 32-bit constant
- return LITERAL_REG;
+ union {
+ float F;
+ uint32_t I;
+ } Imm;
+ Imm.F = MO.getFPImm();
+ return Imm.I;
} else{
llvm_unreachable("Encoding of this operand type is not supported yet.");
}
@@ -176,12 +174,6 @@ unsigned SIMCCodeEmitter::GPR4AlignEncode(const MCInst &MI,
return GPRAlign(MI, OpNo, 2);
}
-uint64_t SIMCCodeEmitter::i32LiteralEncode(const MCInst &MI,
- unsigned OpNo,
- SmallVectorImpl<MCFixup> &Fixup) const {
- return LITERAL_REG | (MI.getOperand(OpNo).getImm() << 32);
-}
-
#define SMRD_OFFSET_MASK 0xff
#define SMRD_IMM_SHIFT 8
#define SMRD_SBASE_MASK 0x3f
@@ -262,17 +254,13 @@ unsigned SIMCCodeEmitter::getEncodingType(const MCInst &MI) const {
unsigned SIMCCodeEmitter::getEncodingBytes(const MCInst &MI) const {
- // Instructions with literal constants are expanded to 64-bits, and
- // the constant is stored in bits [63:32]
- for (unsigned i = 0; i < MI.getNumOperands(); i++) {
- if (MI.getOperand(i).isFPImm()) {
- return 8;
- }
- }
-
- // This instruction always has a literal
- if (MI.getOpcode() == AMDGPU::S_MOV_IMM_I32) {
- return 8;
+ // These instructions aren't real instructions with an encoding type, so
+ // we need to manually specify their size.
+ switch (MI.getOpcode()) {
+ default: break;
+ case AMDGPU::SI_LOAD_LITERAL_I32:
+ case AMDGPU::SI_LOAD_LITERAL_F32:
+ return 4;
}
unsigned encoding_type = getEncodingType(MI);
@@ -294,6 +282,7 @@ unsigned SIMCCodeEmitter::getRegBinaryCode(unsigned reg) const {
switch (reg) {
case AMDGPU::M0: return 124;
case AMDGPU::SREG_LIT_0: return 128;
+ case AMDGPU::SI_LITERAL_CONSTANT: return 255;
default: return getHWRegNum(reg);
}
}
diff --git a/src/gallium/drivers/radeon/Makefile.sources b/src/gallium/drivers/radeon/Makefile.sources
index 687acb3..2eb1120 100644
--- a/src/gallium/drivers/radeon/Makefile.sources
+++ b/src/gallium/drivers/radeon/Makefile.sources
@@ -46,6 +46,7 @@ CPP_SOURCES := \
SIAssignInterpRegs.cpp \
SIInstrInfo.cpp \
SIISelLowering.cpp \
+ SILowerLiteralConstants.cpp \
SIMachineFunctionInfo.cpp \
SIRegisterInfo.cpp \
InstPrinter/AMDGPUInstPrinter.cpp \
diff --git a/src/gallium/drivers/radeon/SIGenRegisterInfo.pl b/src/gallium/drivers/radeon/SIGenRegisterInfo.pl
index 84f677e..e47fb56 100644
--- a/src/gallium/drivers/radeon/SIGenRegisterInfo.pl
+++ b/src/gallium/drivers/radeon/SIGenRegisterInfo.pl
@@ -91,6 +91,7 @@ def VCC : SIReg<"VCC">;
def EXEC : SIReg<"EXEC">;
def SCC : SIReg<"SCC">;
def SREG_LIT_0 : SIReg <"S LIT 0">;
+def SI_LITERAL_CONSTANT : SIReg<"LITERAL CONSTANT">;
def M0 : SIReg <"M0">;
diff --git a/src/gallium/drivers/radeon/SIISelLowering.h b/src/gallium/drivers/radeon/SIISelLowering.h
index 77d61d8..80c7f4b 100644
--- a/src/gallium/drivers/radeon/SIISelLowering.h
+++ b/src/gallium/drivers/radeon/SIISelLowering.h
@@ -29,6 +29,8 @@ class SITargetLowering : public AMDGPUTargetLowering
/// write.
void AppendS_WAITCNT(MachineInstr *MI, MachineBasicBlock &BB,
MachineBasicBlock::iterator I) const;
+ void LowerMOV_IMM(MachineInstr *MI, MachineBasicBlock &BB,
+ MachineBasicBlock::iterator I, unsigned Opocde) const;
void LowerSI_INTERP(MachineInstr *MI, MachineBasicBlock &BB,
MachineBasicBlock::iterator I, MachineRegisterInfo & MRI) const;
void LowerSI_INTERP_CONST(MachineInstr *MI, MachineBasicBlock &BB,
diff --git a/src/gallium/drivers/radeon/SIInstrInfo.td b/src/gallium/drivers/radeon/SIInstrInfo.td
index a7ce9a6..135f279 100644
--- a/src/gallium/drivers/radeon/SIInstrInfo.td
+++ b/src/gallium/drivers/radeon/SIInstrInfo.td
@@ -86,16 +86,6 @@ class GPR2Align <RegisterClass rc, ValueType vt> : Operand <vt> {
let MIOperandInfo = (ops rc:$reg);
}
-def i32Literal : Operand <i32> {
- let EncoderMethod = "i32LiteralEncode";
-}
-
-// i64Literal uses the same encoder method as i32 literal, because an
-// i64Literal is really a i32 literal with the top 32-bits all set to zero.
-def i64Literal : Operand <i64> {
- let EncoderMethod = "i32LiteralEncode";
-}
-
def SMRDmemrr : Operand<iPTR> {
let MIOperandInfo = (ops SReg_64, SReg_32);
let EncoderMethod = "GPR2AlignEncode";
diff --git a/src/gallium/drivers/radeon/SIInstructions.td b/src/gallium/drivers/radeon/SIInstructions.td
index 7802ec6..291c034 100644
--- a/src/gallium/drivers/radeon/SIInstructions.td
+++ b/src/gallium/drivers/radeon/SIInstructions.td
@@ -887,21 +887,21 @@ def S_BFE_I64 : SOP2_64 <0x0000002a, "S_BFE_I64", []>;
//def S_CBRANCH_G_FORK : SOP2_ <0x0000002b, "S_CBRANCH_G_FORK", []>;
def S_ABSDIFF_I32 : SOP2_32 <0x0000002c, "S_ABSDIFF_I32", []>;
-class V_MOV_IMM <Operand immType, SDNode immNode> : VOP1 <
- 0x1,
+class V_MOV_IMM <Operand immType, SDNode immNode> : InstSI <
(outs VReg_32:$dst),
(ins immType:$src0),
"V_MOV_IMM",
[(set VReg_32:$dst, (immNode:$src0))]
>;
+let isCodeGenOnly = 1, isPseudo = 1 in {
+
def V_MOV_IMM_I32 : V_MOV_IMM<i32imm, imm>;
def V_MOV_IMM_F32 : V_MOV_IMM<f32imm, fpimm>;
-def S_MOV_IMM_I32 : SOP1 <
- 0x3,
+def S_MOV_IMM_I32 : InstSI <
(outs SReg_32:$dst),
- (ins i32Literal:$src0),
+ (ins i32imm:$src0),
"S_MOV_IMM_I32",
[(set SReg_32:$dst, (imm:$src0))]
>;
@@ -910,14 +910,25 @@ def S_MOV_IMM_I32 : SOP1 <
// type for indices on load and store instructions. The pattern for
// S_MOV_IMM_I64 will only match i64 immediates that can fit into 32-bits,
// which the hardware can handle.
-def S_MOV_IMM_I64 : SOP1 <
- 0x3,
+def S_MOV_IMM_I64 : InstSI <
(outs SReg_64:$dst),
- (ins i64Literal:$src0),
+ (ins i64imm:$src0),
"S_MOV_IMM_I64 $dst, $src0",
[(set SReg_64:$dst, (IMM32bitIn64bit:$src0))]
>;
+} // End isCodeGenOnly, isPseudo = 1
+
+class SI_LOAD_LITERAL<Operand ImmType> :
+ Enc32 <(outs), (ins ImmType:$imm), "LOAD_LITERAL $imm", []> {
+
+ bits<32> imm;
+ let Inst{31-0} = imm;
+}
+
+def SI_LOAD_LITERAL_I32 : SI_LOAD_LITERAL<i32imm>;
+def SI_LOAD_LITERAL_F32 : SI_LOAD_LITERAL<f32imm>;
+
let isCodeGenOnly = 1, isPseudo = 1 in {
def SET_M0 : InstSI <
diff --git a/src/gallium/drivers/radeon/SILowerLiteralConstants.cpp b/src/gallium/drivers/radeon/SILowerLiteralConstants.cpp
new file mode 100644
index 0000000..7202450
--- /dev/null
+++ b/src/gallium/drivers/radeon/SILowerLiteralConstants.cpp
@@ -0,0 +1,105 @@
+//===-- SILowerLiteralConstants.cpp - Lower intrs using literal constants--===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This pass performs the following transformation on instructions with
+// literal constants:
+//
+// %VGPR0 = V_MOV_IMM_I32 1
+//
+// becomes:
+//
+// BUNDLE
+// * %VGPR = V_MOV_B32_32 SI_LITERAL_CONSTANT
+// * SI_LOAD_LITERAL 1
+//
+// The resulting sequence matches exactly how the hardware handles immediate
+// operands, so this transformation greatly simplifies the code generator.
+//
+// Only the *_MOV_IMM_* support immediate operands at the moment, but when
+// support for immediate operands is added to other instructions, they
+// will be lowered here as well.
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPU.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineInstrBundle.h"
+
+using namespace llvm;
+
+namespace {
+
+class SILowerLiteralConstantsPass : public MachineFunctionPass {
+
+private:
+ static char ID;
+ const TargetInstrInfo *TII;
+
+public:
+ SILowerLiteralConstantsPass(TargetMachine &tm) :
+ MachineFunctionPass(ID), TII(tm.getInstrInfo()) { }
+
+ virtual bool runOnMachineFunction(MachineFunction &MF);
+
+ const char *getPassName() const {
+ return "SI Lower literal constants pass";
+ }
+};
+
+} // End anonymous namespace
+
+char SILowerLiteralConstantsPass::ID = 0;
+
+FunctionPass *llvm::createSILowerLiteralConstantsPass(TargetMachine &tm) {
+ return new SILowerLiteralConstantsPass(tm);
+}
+
+bool SILowerLiteralConstantsPass::runOnMachineFunction(MachineFunction &MF) {
+ for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end();
+ BB != BB_E; ++BB) {
+ MachineBasicBlock &MBB = *BB;
+ for (MachineBasicBlock::iterator I = MBB.begin(), Next = llvm::next(I);
+ I != MBB.end(); I = Next, Next = llvm::next(I)) {
+ MachineInstr &MI = *I;
+ switch (MI.getOpcode()) {
+ default: break;
+ case AMDGPU::S_MOV_IMM_I32:
+ case AMDGPU::S_MOV_IMM_I64:
+ case AMDGPU::V_MOV_IMM_F32:
+ case AMDGPU::V_MOV_IMM_I32: {
+ unsigned MovOpcode;
+ unsigned LoadLiteralOpcode;
+ MachineOperand LiteralOp = MI.getOperand(1);
+ if (AMDGPU::VReg_32RegClass.contains(MI.getOperand(0).getReg())) {
+ MovOpcode = AMDGPU::V_MOV_B32_e32;
+ } else {
+ MovOpcode = AMDGPU::S_MOV_B32;
+ }
+ if (LiteralOp.isImm()) {
+ LoadLiteralOpcode = AMDGPU::SI_LOAD_LITERAL_I32;
+ } else {
+ LoadLiteralOpcode = AMDGPU::SI_LOAD_LITERAL_F32;
+ }
+ MachineInstr *First =
+ BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(MovOpcode),
+ MI.getOperand(0).getReg())
+ .addReg(AMDGPU::SI_LITERAL_CONSTANT);
+ MachineInstr *Last =
+ BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(LoadLiteralOpcode))
+ .addOperand(MI.getOperand(1));
+ Last->setIsInsideBundle();
+ llvm::finalizeBundle(MBB, First, Last);
+ MI.eraseFromParent();
+ break;
+ }
+ }
+ }
+ }
+ return false;
+}
More information about the mesa-commit
mailing list