[llvm] 4dd5d96 - [RISCV] Don't call use_nodbg_operands for physical registers in RISCVOptWInstrs hasAllNBitUsers. (#77032)
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Fri Jan 5 09:22:58 PST 2024
Author: Craig Topper
Date: 2024-01-05T09:22:54-08:00
New Revision: 4dd5d967975fa8d52b8c60596d892d9dd5615809
URL: https://github.com/llvm/llvm-project/commit/4dd5d967975fa8d52b8c60596d892d9dd5615809
DIFF: https://github.com/llvm/llvm-project/commit/4dd5d967975fa8d52b8c60596d892d9dd5615809.diff
LOG: [RISCV] Don't call use_nodbg_operands for physical registers in RISCVOptWInstrs hasAllNBitUsers. (#77032)
The ADDIW in the new test case was incorrectly removed due to
incorrectly following the x10 register from the return value back to the
argument. This is due to use_nodbg_operands returning every instruction
that uses a physical register regardless of the data flow.
Added:
Modified:
llvm/lib/Target/RISCV/RISCVOptWInstrs.cpp
llvm/test/CodeGen/RISCV/opt-w-instrs.mir
Removed:
################################################################################
diff --git a/llvm/lib/Target/RISCV/RISCVOptWInstrs.cpp b/llvm/lib/Target/RISCV/RISCVOptWInstrs.cpp
index 2c2b34bb5b7797..c16eee67f3c5c5 100644
--- a/llvm/lib/Target/RISCV/RISCVOptWInstrs.cpp
+++ b/llvm/lib/Target/RISCV/RISCVOptWInstrs.cpp
@@ -126,7 +126,11 @@ static bool hasAllNBitUsers(const MachineInstr &OrigMI,
if (MI->getNumExplicitDefs() != 1)
return false;
- for (auto &UserOp : MRI.use_nodbg_operands(MI->getOperand(0).getReg())) {
+ Register DestReg = MI->getOperand(0).getReg();
+ if (!DestReg.isVirtual())
+ return false;
+
+ for (auto &UserOp : MRI.use_nodbg_operands(DestReg)) {
const MachineInstr *UserMI = UserOp.getParent();
unsigned OpIdx = UserOp.getOperandNo();
diff --git a/llvm/test/CodeGen/RISCV/opt-w-instrs.mir b/llvm/test/CodeGen/RISCV/opt-w-instrs.mir
index 0ecf8fd6bef33a..ebac5a42fbcda0 100644
--- a/llvm/test/CodeGen/RISCV/opt-w-instrs.mir
+++ b/llvm/test/CodeGen/RISCV/opt-w-instrs.mir
@@ -28,3 +28,23 @@ body: |
$x11 = COPY %4
PseudoRET
...
+
+---
+name: physreg
+tracksRegLiveness: true
+body: |
+ bb.0.entry:
+ liveins: $x10, $x11
+
+ ; CHECK-ZFA-LABEL: name: physreg
+ ; CHECK-ZFA: liveins: $x10, $x11
+ ; CHECK-ZFA-NEXT: {{ $}}
+ ; CHECK-ZFA-NEXT: [[COPY:%[0-9]+]]:gpr = COPY $x10
+ ; CHECK-ZFA-NEXT: [[ADDIW:%[0-9]+]]:gpr = ADDIW [[COPY]], 0
+ ; CHECK-ZFA-NEXT: $x10 = COPY [[ADDIW]]
+ ; CHECK-ZFA-NEXT: PseudoRET
+ %0:gpr = COPY $x10
+ %1:gpr = ADDIW %0, 0
+ $x10 = COPY %1
+ PseudoRET
+...
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