[llvm] [RISCV] Add short forward branch support for `lb`, `lbu`, `lh`, `lhu`, `lw`, `lwu` and `ld` (PR #170829)

[Min-Yih Hsu via llvm-commits]

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@@ -897,6 +897,74 @@ MachineInstr *RISCVInstrInfo::foldMemoryOperandImpl(
       .addImm(0);
 }
 
+unsigned getLoadPredicatedOpcode(unsigned Opcode) {
+  switch (Opcode) {
+  case RISCV::LB:
+    return RISCV::PseudoCCLB;
+  case RISCV::LBU:
+    return RISCV::PseudoCCLBU;
+  case RISCV::LH:
+    return RISCV::PseudoCCLH;
+  case RISCV::LHU:
+    return RISCV::PseudoCCLHU;
+  case RISCV::LW:
+    return RISCV::PseudoCCLW;
+  case RISCV::LWU:
+    return RISCV::PseudoCCLWU;
+  case RISCV::LD:
+    return RISCV::PseudoCCLD;
+  default:
+    return 0;
+  }
+}
+
+MachineInstr *RISCVInstrInfo::foldMemoryOperandImpl(
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mshockwave wrote:

does it make sense to do the same folding with the FrameIndex variant?

https://github.com/llvm/llvm-project/pull/170829