[llvm] [RISCV][VLOPT] Add getOperandInfo for integer and floating point widening reductions (PR #122176)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

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

Author: Michael Maitland (michaelmaitland)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/122176.diff


2 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp (+16) 
- (modified) llvm/test/CodeGen/RISCV/rvv/vl-opt-op-info.mir (+51) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp b/llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp
index ad61a77df90573..1ff5e01256379f 100644
--- a/llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp
+++ b/llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp
@@ -710,6 +710,22 @@ getOperandLog2EEW(const MachineOperand &MO, const MachineRegisterInfo *MRI) {
     return MILog2SEW;
   }
 
+  // Vector Widening Integer Reduction Instructions
+  // The Dest and VS1 read only element 0 for the vector register. Return 2*EEW
+  // for these. VS2 has EEW=SEW and EMUL=LMUL.
+  case RISCV::VWREDSUM_VS:
+  case RISCV::VWREDSUMU_VS:
+  // Vector Widening Floating-Point Reduction Instructions
+  case RISCV::VFWREDOSUM_VS:
+  case RISCV::VFWREDUSUM_VS: {
+    bool TwoTimes = IsMODef || MO.getOperandNo() == 3;
+    unsigned Log2EEW = TwoTimes ? MILog2SEW + 1 : MILog2SEW;
+    if (MO.getOperandNo() == 2)
+      return OperandInfo(
+          RISCVVType::getEMULEqualsEEWDivSEWTimesLMUL(Log2EEW, MI), Log2EEW);
+    return OperandInfo(Log2EEW);
+  }
+
   default:
     return std::nullopt;
   }
diff --git a/llvm/test/CodeGen/RISCV/rvv/vl-opt-op-info.mir b/llvm/test/CodeGen/RISCV/rvv/vl-opt-op-info.mir
index c4a38345461038..28f711c6c1cf8c 100644
--- a/llvm/test/CodeGen/RISCV/rvv/vl-opt-op-info.mir
+++ b/llvm/test/CodeGen/RISCV/rvv/vl-opt-op-info.mir
@@ -1224,6 +1224,7 @@ body: |
     %x:vr = PseudoVMAND_MM_B1 $noreg, $noreg, -1, 0
     %y:vr = PseudoVIOTA_M_MF2 $noreg, %x, 1, 3 /* e8 */, 0
 ...
+---
 name: vred_vs2
 body: |
   bb.0:
@@ -1337,3 +1338,53 @@ body: |
     %y:vr = PseudoVREDSUM_VS_M1_E8 $noreg, $noreg, %x, 1, 3 /* e8 */, 0
     %z:vr = PseudoVADD_VV_M1 $noreg, %x, $noreg, 2, 3 /* e8 */, 0
 ...
+---
+name: vwred_vs2
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vred_vs2
+    ; CHECK: %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, 1, 3 /* e8 */, 0 /* tu, mu */
+    ; CHECK-NEXT: %y:vr = PseudoVREDAND_VS_M1_E8 $noreg, %x, $noreg, 1, 3 /* e8 */, 0 /* tu, mu */
+    %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 4 /* e16 */, 0
+    %y:vr = PseudoVWREDSUM_VS_M1_E8 $noreg, $noreg, %x, 1, 3 /* e8 */, 0
+...
+---
+name: vwred_vs1
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vwred_vs1
+    ; CHECK: %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, 1, 3 /* e8 */, 0 /* tu, mu */
+    ; CHECK-NEXT: %y:vr = PseudoVWREDSUM_VS_M1_E8 $noreg, %x, $noreg, 1, 3 /* e8 */, 0 /* tu, mu */
+    %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 3 /* e8 */, 0
+    %y:vr = PseudoVWREDSUM_VS_M1_E8 $noreg, %x, $noreg, 1, 3 /* e8 */, 0
+...
+---
+name: vwred_vs1_incompatible_eew
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vwred_vs1_incompatible_eew
+    ; CHECK: %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 4 /* e16 */, 0 /* tu, mu */
+    ; CHECK-NEXT: %y:vr = PseudoVWREDSUM_VS_M1_E8 $noreg, %x, $noreg, 1, 3 /* e8 */, 0 /* tu, mu */
+    %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 4 /* e16 */, 0
+    %y:vr = PseudoVWREDSUM_VS_M1_E8 $noreg, %x, $noreg, 1, 3 /* e8 */, 0
+...
+---
+name: vwred_vs2_incompatible_eew
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vwred_vs2_incompatible_eew
+    ; CHECK: %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 3 /* e8 */, 0 /* tu, mu */
+    ; CHECK-NEXT: %y:vr = PseudoVWREDSUM_VS_M1_E8 $noreg, $noreg, %x, 1, 3 /* e8 */, 0 /* tu, mu */
+    %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 3 /* e8 */, 0
+    %y:vr = PseudoVWREDSUM_VS_M1_E8 $noreg, $noreg, %x, 1, 3 /* e8 */, 0
+...
+---
+name: vwred_incompatible_emul
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vwred_vs1_incompatible_emul
+    ; CHECK: %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 3 /* e8 */, 0 /* tu, mu */
+    ; CHECK-NEXT: %y:vr = PseudoVWREDSUM_VS_MF2_E8 $noreg, %x, $noreg, 1, 3 /* e8 */, 0 /* tu, mu */
+    %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 3 /* e8 */, 0
+    %y:vr = PseudoVWREDSUM_VS_MF2_E8 $noreg, %x, $noreg, 1, 3 /* e8 */, 0
+...

``````````

</details>


https://github.com/llvm/llvm-project/pull/122176