[RISCV][VLOpt] Kill all uses of and remove twoTimesVLMUL [NFC]

[preames]

Case analysis:

• EEW=SEW*2, getEMULEqualsEEWDivSEWTimesLMUL(EEW) returns 2 x VLMUL
• EEW=SEW, getEMULEqualsEEWDivSEWTimesLMUL(EEW) returns VLMUL

[llvmbot]

@llvm/pr-subscribers-backend-risc-v

Author: Philip Reames (preames)

Changes

Case analysis:

• EEW=SEW*2, getEMULEqualsEEWDivSEWTimesLMUL(EEW) returns 2 x VLMUL
• EEW=SEW, getEMULEqualsEEWDivSEWTimesLMUL(EEW) returns VLMUL

---

Full diff: https://github.com/llvm/llvm-project/pull/122003.diff

1 Files Affected:

• (modified) llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp (+6-31)

diff --git a/llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp b/llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp
index 32d552625a8e8b..ff4cbac84d4d45 100644
--- a/llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp
+++ b/llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp
@@ -129,28 +129,6 @@ static raw_ostream &operator<<(raw_ostream &OS, const OperandInfo &OI) {
 
 namespace llvm {
 namespace RISCVVType {
-/// Return the RISCVII::VLMUL that is two times VLMul.
-/// Precondition: VLMul is not LMUL_RESERVED or LMUL_8.
-static RISCVII::VLMUL twoTimesVLMUL(RISCVII::VLMUL VLMul) {
-  switch (VLMul) {
-  case RISCVII::VLMUL::LMUL_F8:
-    return RISCVII::VLMUL::LMUL_F4;
-  case RISCVII::VLMUL::LMUL_F4:
-    return RISCVII::VLMUL::LMUL_F2;
-  case RISCVII::VLMUL::LMUL_F2:
-    return RISCVII::VLMUL::LMUL_1;
-  case RISCVII::VLMUL::LMUL_1:
-    return RISCVII::VLMUL::LMUL_2;
-  case RISCVII::VLMUL::LMUL_2:
-    return RISCVII::VLMUL::LMUL_4;
-  case RISCVII::VLMUL::LMUL_4:
-    return RISCVII::VLMUL::LMUL_8;
-  case RISCVII::VLMUL::LMUL_8:
-  default:
-    llvm_unreachable("Could not multiply VLMul by 2");
-  }
-}
-
 /// Return EMUL = (EEW / SEW) * LMUL where EEW comes from Log2EEW and LMUL and
 /// SEW are from the TSFlags of MI.
 static std::pair<unsigned, bool>
@@ -559,9 +537,8 @@ static OperandInfo getOperandInfo(const MachineOperand &MO,
   case RISCV::VFWCVT_F_X_V:
   case RISCV::VFWCVT_F_F_V: {
     unsigned Log2EEW = IsMODef ? MILog2SEW + 1 : MILog2SEW;
-    RISCVII::VLMUL EMUL =
-        IsMODef ? RISCVVType::twoTimesVLMUL(MIVLMul) : MIVLMul;
-    return OperandInfo(EMUL, Log2EEW);
+    return OperandInfo(RISCVVType::getEMULEqualsEEWDivSEWTimesLMUL(Log2EEW, MI),
+                       Log2EEW);
   }
 
   // Def and Op1 uses EEW=2*SEW and EMUL=2*LMUL. Op2 uses EEW=SEW and EMUL=LMUL
@@ -581,9 +558,8 @@ static OperandInfo getOperandInfo(const MachineOperand &MO,
     bool IsOp1 = HasPassthru ? MO.getOperandNo() == 2 : MO.getOperandNo() == 1;
     bool TwoTimes = IsMODef || IsOp1;
     unsigned Log2EEW = TwoTimes ? MILog2SEW + 1 : MILog2SEW;
-    RISCVII::VLMUL EMUL =
-        TwoTimes ? RISCVVType::twoTimesVLMUL(MIVLMul) : MIVLMul;
-    return OperandInfo(EMUL, Log2EEW);
+    return OperandInfo(RISCVVType::getEMULEqualsEEWDivSEWTimesLMUL(Log2EEW, MI),
+                       Log2EEW);
   }
 
   // Vector Integer Extension
@@ -626,9 +602,8 @@ static OperandInfo getOperandInfo(const MachineOperand &MO,
     bool IsOp1 = HasPassthru ? MO.getOperandNo() == 2 : MO.getOperandNo() == 1;
     bool TwoTimes = IsOp1;
     unsigned Log2EEW = TwoTimes ? MILog2SEW + 1 : MILog2SEW;
-    RISCVII::VLMUL EMUL =
-        TwoTimes ? RISCVVType::twoTimesVLMUL(MIVLMul) : MIVLMul;
-    return OperandInfo(EMUL, Log2EEW);
+    return OperandInfo(RISCVVType::getEMULEqualsEEWDivSEWTimesLMUL(Log2EEW, MI),
+                       Log2EEW);
   }
 
   // Vector Mask Instructions

[topperc]

LGTM

[michaelmaitland]

LGTM

[llvm-ci]

LLVM Buildbot has detected a new failure on builder openmp-offload-libc-amdgpu-runtime running on omp-vega20-1 while building llvm at step 6 "test-openmp".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/73/builds/11325

Here is the relevant piece of the build log for the reference

Step 6 (test-openmp) failure: test (failure)
******************** TEST 'libomp :: tasking/issue-94260-2.c' FAILED ********************
Exit Code: -11

Command Output (stdout):
--
# RUN: at line 1
/home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./bin/clang -fopenmp   -I /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/src -I /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/openmp/runtime/test -L /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/src  -fno-omit-frame-pointer -I /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/openmp/runtime/test/ompt /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/openmp/runtime/test/tasking/issue-94260-2.c -o /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/test/tasking/Output/issue-94260-2.c.tmp -lm -latomic && /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/test/tasking/Output/issue-94260-2.c.tmp
# executed command: /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./bin/clang -fopenmp -I /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/src -I /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/openmp/runtime/test -L /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/src -fno-omit-frame-pointer -I /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/openmp/runtime/test/ompt /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/openmp/runtime/test/tasking/issue-94260-2.c -o /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/test/tasking/Output/issue-94260-2.c.tmp -lm -latomic
# executed command: /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/test/tasking/Output/issue-94260-2.c.tmp
# note: command had no output on stdout or stderr
# error: command failed with exit status: -11

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