[llvm] 65f9992 - [RISCV] Add PseudoCCMOVGPR to RISCVSExtWRemoval.

[Craig Topper via llvm-commits]

Author: Craig Topper
Date: 2022-11-14T13:39:00-08:00
New Revision: 65f99928654869ea17aad00f2c5209f4a5f9d1dd

URL: https://github.com/llvm/llvm-project/commit/65f99928654869ea17aad00f2c5209f4a5f9d1dd
DIFF: https://github.com/llvm/llvm-project/commit/65f99928654869ea17aad00f2c5209f4a5f9d1dd.diff

LOG: [RISCV] Add PseudoCCMOVGPR to RISCVSExtWRemoval.

This instruction is a conditional move. It propagates sign bits
from its inputs.

Added: 
    

Modified: 
    llvm/lib/Target/RISCV/RISCVSExtWRemoval.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/RISCV/RISCVSExtWRemoval.cpp b/llvm/lib/Target/RISCV/RISCVSExtWRemoval.cpp
index 1d57c8c725429..c040e01ad5cf4 100644
--- a/llvm/lib/Target/RISCV/RISCVSExtWRemoval.cpp
+++ b/llvm/lib/Target/RISCV/RISCVSExtWRemoval.cpp
@@ -211,6 +211,15 @@ static bool hasAllWUsers(const MachineInstr &OrigMI, MachineRegisterInfo &MRI) {
       case RISCV::BINVI:
         Worklist.push_back(UserMI);
         break;
+
+      case RISCV::PseudoCCMOVGPR:
+        // Either operand 4 or operand 5 is returned by this instruction. If
+        // only the lower word of the result is used, then only the lower word
+        // of operand 4 and 5 is used.
+        if (OpIdx != 4 && OpIdx != 5)
+          return false;
+        Worklist.push_back(UserMI);
+        break;
       }
     }
   }
@@ -396,19 +405,24 @@ static bool isSignExtendedW(MachineInstr &OrigMI, MachineRegisterInfo &MRI,
     case RISCV::MAXU:
     case RISCV::MIN:
     case RISCV::MINU:
+    case RISCV::PseudoCCMOVGPR:
     case RISCV::PHI: {
       // If all incoming values are sign-extended, the output of AND, OR, XOR,
       // MIN, MAX, or PHI is also sign-extended.
 
       // The input registers for PHI are operand 1, 3, ...
+      // The input registers for PseudoCCMOVGPR are 4 and 5.
       // The input registers for others are operand 1 and 2.
-      unsigned E = 3, D = 1;
+      unsigned B = 1, E = 3, D = 1;
       if (MI->getOpcode() == RISCV::PHI) {
         E = MI->getNumOperands();
         D = 2;
+      } else if (MI->getOpcode() == RISCV::PseudoCCMOVGPR) {
+        B = 4;
+        E = 6;
       }
 
-      for (unsigned I = 1; I != E; I += D) {
+      for (unsigned I = B; I != E; I += D) {
         if (!MI->getOperand(I).isReg())
           return false;