[llvm] f9c9088 - [RISCV] Split TuneShiftedZExtFusion (#76032)
via llvm-commits
llvm-commits at lists.llvm.org
Thu Dec 21 22:37:30 PST 2023
Author: Wang Pengcheng
Date: 2023-12-22T14:37:26+08:00
New Revision: f9c908862a34b464694087705ebaf070f87f251c
URL: https://github.com/llvm/llvm-project/commit/f9c908862a34b464694087705ebaf070f87f251c
DIFF: https://github.com/llvm/llvm-project/commit/f9c908862a34b464694087705ebaf070f87f251c.diff
LOG: [RISCV] Split TuneShiftedZExtFusion (#76032)
We split `TuneShiftedZExtFusion` into three fusions to make them
reusable and match the GCC implementation[1].
The zexth/zextw fusions can be reused by XiangShan[2] and other
commercial processors, but shifted zero extension is not so common.
`macro-fusions-veyron-v1.mir` is renamed so it's not relevant to
specific processor.
References:
[1] https://gcc.gnu.org/pipermail/gcc-patches/2023-November/637303.html
[2] https://xiangshan-doc.readthedocs.io/zh_CN/latest/frontend/decode
Added:
llvm/test/CodeGen/RISCV/macro-fusions.mir
Modified:
llvm/lib/Target/RISCV/RISCVFeatures.td
llvm/lib/Target/RISCV/RISCVMacroFusion.cpp
llvm/lib/Target/RISCV/RISCVProcessors.td
llvm/lib/Target/RISCV/RISCVSubtarget.h
Removed:
llvm/test/CodeGen/RISCV/macro-fusions-veyron-v1.mir
################################################################################
diff --git a/llvm/lib/Target/RISCV/RISCVFeatures.td b/llvm/lib/Target/RISCV/RISCVFeatures.td
index 5048e28545a3cb..a66dd135ae5f89 100644
--- a/llvm/lib/Target/RISCV/RISCVFeatures.td
+++ b/llvm/lib/Target/RISCV/RISCVFeatures.td
@@ -977,9 +977,19 @@ def TuneLUIADDIFusion
def TuneAUIPCADDIFusion
: SubtargetFeature<"auipc-addi-fusion", "HasAUIPCADDIFusion",
"true", "Enable AUIPC+ADDI macrofusion">;
-def TuneShiftedZExtFusion
- : SubtargetFeature<"shifted-zext-fusion", "HasShiftedZExtFusion",
- "true", "Enable SLLI+SRLI to be fused when computing (shifted) zero extension">;
+
+def TuneZExtHFusion
+ : SubtargetFeature<"zexth-fusion", "HasZExtHFusion",
+ "true", "Enable SLLI+SRLI to be fused to zero extension of halfword">;
+
+def TuneZExtWFusion
+ : SubtargetFeature<"zextw-fusion", "HasZExtWFusion",
+ "true", "Enable SLLI+SRLI to be fused to zero extension of word">;
+
+def TuneShiftedZExtWFusion
+ : SubtargetFeature<"shifted-zextw-fusion", "HasShiftedZExtWFusion",
+ "true", "Enable SLLI+SRLI to be fused when computing (shifted) zero extension of word">;
+
def TuneLDADDFusion
: SubtargetFeature<"ld-add-fusion", "HasLDADDFusion",
"true", "Enable LD+ADD macrofusion.">;
diff --git a/llvm/lib/Target/RISCV/RISCVMacroFusion.cpp b/llvm/lib/Target/RISCV/RISCVMacroFusion.cpp
index 02ea5270823d8d..f948f05b22f772 100644
--- a/llvm/lib/Target/RISCV/RISCVMacroFusion.cpp
+++ b/llvm/lib/Target/RISCV/RISCVMacroFusion.cpp
@@ -58,18 +58,66 @@ static bool isLDADD(const MachineInstr *FirstMI, const MachineInstr &SecondMI) {
return checkRegisters(FirstMI->getOperand(0).getReg(), SecondMI);
}
-// Fuse these patterns:
-//
-// slli rd, rs1, 32
-// srli rd, rd, x
-// where 0 <= x <= 32
-//
-// and
-//
+// Fuse zero extension of halfword:
// slli rd, rs1, 48
+// srli rd, rd, 48
+static bool isZExtH(const MachineInstr *FirstMI, const MachineInstr &SecondMI) {
+ if (SecondMI.getOpcode() != RISCV::SRLI)
+ return false;
+
+ if (!SecondMI.getOperand(2).isImm())
+ return false;
+
+ if (SecondMI.getOperand(2).getImm() != 48)
+ return false;
+
+ // Given SecondMI, when FirstMI is unspecified, we must return
+ // if SecondMI may be part of a fused pair at all.
+ if (!FirstMI)
+ return true;
+
+ if (FirstMI->getOpcode() != RISCV::SLLI)
+ return false;
+
+ if (FirstMI->getOperand(2).getImm() != 48)
+ return false;
+
+ return checkRegisters(FirstMI->getOperand(0).getReg(), SecondMI);
+}
+
+// Fuse zero extension of word:
+// slli rd, rs1, 32
+// srli rd, rd, 32
+static bool isZExtW(const MachineInstr *FirstMI, const MachineInstr &SecondMI) {
+ if (SecondMI.getOpcode() != RISCV::SRLI)
+ return false;
+
+ if (!SecondMI.getOperand(2).isImm())
+ return false;
+
+ if (SecondMI.getOperand(2).getImm() != 32)
+ return false;
+
+ // Given SecondMI, when FirstMI is unspecified, we must return
+ // if SecondMI may be part of a fused pair at all.
+ if (!FirstMI)
+ return true;
+
+ if (FirstMI->getOpcode() != RISCV::SLLI)
+ return false;
+
+ if (FirstMI->getOperand(2).getImm() != 32)
+ return false;
+
+ return checkRegisters(FirstMI->getOperand(0).getReg(), SecondMI);
+}
+
+// Fuse shifted zero extension of word:
+// slli rd, rs1, 32
// srli rd, rd, x
-static bool isShiftedZExt(const MachineInstr *FirstMI,
- const MachineInstr &SecondMI) {
+// where 0 <= x < 32
+static bool isShiftedZExtW(const MachineInstr *FirstMI,
+ const MachineInstr &SecondMI) {
if (SecondMI.getOpcode() != RISCV::SRLI)
return false;
@@ -77,8 +125,7 @@ static bool isShiftedZExt(const MachineInstr *FirstMI,
return false;
unsigned SRLIImm = SecondMI.getOperand(2).getImm();
- bool IsShiftBy48 = SRLIImm == 48;
- if (SRLIImm > 32 && !IsShiftBy48)
+ if (SRLIImm >= 32)
return false;
// Given SecondMI, when FirstMI is unspecified, we must return
@@ -89,8 +136,7 @@ static bool isShiftedZExt(const MachineInstr *FirstMI,
if (FirstMI->getOpcode() != RISCV::SLLI)
return false;
- unsigned SLLIImm = FirstMI->getOperand(2).getImm();
- if (IsShiftBy48 ? (SLLIImm != 48) : (SLLIImm != 32))
+ if (FirstMI->getOperand(2).getImm() != 32)
return false;
return checkRegisters(FirstMI->getOperand(0).getReg(), SecondMI);
@@ -144,7 +190,13 @@ static bool shouldScheduleAdjacent(const TargetInstrInfo &TII,
if (ST.hasAUIPCADDIFusion() && isAUIPCADDI(FirstMI, SecondMI))
return true;
- if (ST.hasShiftedZExtFusion() && isShiftedZExt(FirstMI, SecondMI))
+ if (ST.hasZExtHFusion() && isZExtH(FirstMI, SecondMI))
+ return true;
+
+ if (ST.hasZExtWFusion() && isZExtW(FirstMI, SecondMI))
+ return true;
+
+ if (ST.hasShiftedZExtWFusion() && isShiftedZExtW(FirstMI, SecondMI))
return true;
if (ST.hasLDADDFusion() && isLDADD(FirstMI, SecondMI))
diff --git a/llvm/lib/Target/RISCV/RISCVProcessors.td b/llvm/lib/Target/RISCV/RISCVProcessors.td
index 71c250634cfc90..6362a3bef6f281 100644
--- a/llvm/lib/Target/RISCV/RISCVProcessors.td
+++ b/llvm/lib/Target/RISCV/RISCVProcessors.td
@@ -276,7 +276,9 @@ def VENTANA_VEYRON_V1 : RISCVProcessorModel<"veyron-v1",
[TuneVentanaVeyron,
TuneLUIADDIFusion,
TuneAUIPCADDIFusion,
- TuneShiftedZExtFusion,
+ TuneZExtHFusion,
+ TuneZExtWFusion,
+ TuneShiftedZExtWFusion,
TuneLDADDFusion]>;
def XIANGSHAN_NANHU : RISCVProcessorModel<"xiangshan-nanhu",
diff --git a/llvm/lib/Target/RISCV/RISCVSubtarget.h b/llvm/lib/Target/RISCV/RISCVSubtarget.h
index 7540218633bfcb..26320b05d9be29 100644
--- a/llvm/lib/Target/RISCV/RISCVSubtarget.h
+++ b/llvm/lib/Target/RISCV/RISCVSubtarget.h
@@ -190,8 +190,8 @@ class RISCVSubtarget : public RISCVGenSubtargetInfo {
}
bool hasMacroFusion() const {
- return hasLUIADDIFusion() || hasAUIPCADDIFusion() ||
- hasShiftedZExtFusion() || hasLDADDFusion();
+ return hasLUIADDIFusion() || hasAUIPCADDIFusion() || hasZExtHFusion() ||
+ hasZExtWFusion() || hasShiftedZExtWFusion() || hasLDADDFusion();
}
// Vector codegen related methods.
diff --git a/llvm/test/CodeGen/RISCV/macro-fusions-veyron-v1.mir b/llvm/test/CodeGen/RISCV/macro-fusions.mir
similarity index 83%
rename from llvm/test/CodeGen/RISCV/macro-fusions-veyron-v1.mir
rename to llvm/test/CodeGen/RISCV/macro-fusions.mir
index 6d1e92e997b324..b7568ae6f0f699 100644
--- a/llvm/test/CodeGen/RISCV/macro-fusions-veyron-v1.mir
+++ b/llvm/test/CodeGen/RISCV/macro-fusions.mir
@@ -1,7 +1,7 @@
# REQUIRES: asserts
-# RUN: llc -mtriple=riscv64-linux-gnu -mcpu=veyron-v1 -x=mir < %s \
+# RUN: llc -mtriple=riscv64-linux-gnu -x=mir < %s \
# RUN: -debug-only=machine-scheduler -start-before=machine-scheduler 2>&1 \
-# RUN: -mattr=+lui-addi-fusion,+auipc-addi-fusion,+shifted-zext-fusion,+ld-add-fusion \
+# RUN: -mattr=+lui-addi-fusion,+auipc-addi-fusion,+zexth-fusion,+zextw-fusion,+shifted-zextw-fusion,+ld-add-fusion \
# RUN: | FileCheck %s
# CHECK: lui_addi:%bb.0
@@ -38,10 +38,10 @@ body: |
PseudoRET
...
-# CHECK: slli_srli
+# CHECK: slli_srli_shifted_zext
# CHECK: Macro fuse: {{.*}}SLLI - SRLI
---
-name: slli_srli
+name: shifted_zext
tracksRegLiveness: true
body: |
bb.0.entry:
@@ -55,10 +55,10 @@ body: |
PseudoRET
...
-# CHECK: slli_srli_48
+# CHECK: slli_srli_zexth
# CHECK: Macro fuse: {{.*}}SLLI - SRLI
---
-name: slli_srli_48
+name: zexth
tracksRegLiveness: true
body: |
bb.0.entry:
@@ -72,6 +72,23 @@ body: |
PseudoRET
...
+# CHECK: slli_srli_zextw
+# CHECK: Macro fuse: {{.*}}SLLI - SRLI
+---
+name: zextw
+tracksRegLiveness: true
+body: |
+ bb.0.entry:
+ liveins: $x10
+ %1:gpr = COPY $x10
+ %2:gpr = SLLI %1, 32
+ %3:gpr = XORI %1, 3
+ %4:gpr = SRLI %2, 32
+ $x10 = COPY %3
+ $x11 = COPY %4
+ PseudoRET
+...
+
# CHECK: slli_srli_no_fusion_0
# CHECK-NOT: Macro fuse: {{.*}}SLLI - SRLI
---
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