[llvm] [RISCV] Use RISCVInstrInfo::movImm to implement most of RISCVPostRAExpandPseudo::expandMovImm (PR #70389)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

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

Author: Craig Topper (topperc)

<details>
<summary>Changes</summary>

There are two commits. The first is a bit of refactoring to increase similarity and fix a bug that was already fixed in movImm. The second does the merging

---
Full diff: https://github.com/llvm/llvm-project/pull/70389.diff


3 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVInstrInfo.cpp (+23-9) 
- (modified) llvm/lib/Target/RISCV/RISCVInstrInfo.h (+2-1) 
- (modified) llvm/lib/Target/RISCV/RISCVPostRAExpandPseudoInsts.cpp (+4-43) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
index 0abf302bb25e310..e9c87f7b7b574cc 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
@@ -737,7 +737,8 @@ MachineInstr *RISCVInstrInfo::foldMemoryOperandImpl(
 void RISCVInstrInfo::movImm(MachineBasicBlock &MBB,
                             MachineBasicBlock::iterator MBBI,
                             const DebugLoc &DL, Register DstReg, uint64_t Val,
-                            MachineInstr::MIFlag Flag) const {
+                            MachineInstr::MIFlag Flag, bool DstRenamable,
+                            bool DstIsDead) const {
   Register SrcReg = RISCV::X0;
 
   if (!STI.is64Bit() && !isInt<32>(Val))
@@ -747,28 +748,40 @@ void RISCVInstrInfo::movImm(MachineBasicBlock &MBB,
       RISCVMatInt::generateInstSeq(Val, STI.getFeatureBits());
   assert(!Seq.empty());
 
+  bool SrcRenamable = false;
+  unsigned Num = 0;
+
   for (const RISCVMatInt::Inst &Inst : Seq) {
+    bool LastItem = ++Num == Seq.size();
+    unsigned DstRegState = getDeadRegState(DstIsDead && LastItem) |
+                           getRenamableRegState(DstRenamable);
+    unsigned SrcRegState = getKillRegState(SrcReg != RISCV::X0) |
+                           getRenamableRegState(SrcRenamable);
     switch (Inst.getOpndKind()) {
     case RISCVMatInt::Imm:
-      BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()), DstReg)
+      BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()))
+          .addReg(DstReg, RegState::Define | DstRegState)
           .addImm(Inst.getImm())
           .setMIFlag(Flag);
       break;
     case RISCVMatInt::RegX0:
-      BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()), DstReg)
-          .addReg(SrcReg, getKillRegState(SrcReg != RISCV::X0))
+      BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()))
+          .addReg(DstReg, RegState::Define | DstRegState)
+          .addReg(SrcReg, SrcRegState)
           .addReg(RISCV::X0)
           .setMIFlag(Flag);
       break;
     case RISCVMatInt::RegReg:
-      BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()), DstReg)
-          .addReg(SrcReg, getKillRegState(SrcReg != RISCV::X0))
-          .addReg(SrcReg, getKillRegState(SrcReg != RISCV::X0))
+      BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()))
+          .addReg(DstReg, RegState::Define | DstRegState)
+          .addReg(SrcReg, SrcRegState)
+          .addReg(SrcReg, SrcRegState)
           .setMIFlag(Flag);
       break;
     case RISCVMatInt::RegImm:
-      BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()), DstReg)
-          .addReg(SrcReg, getKillRegState(SrcReg != RISCV::X0))
+      BuildMI(MBB, MBBI, DL, get(Inst.getOpcode()))
+          .addReg(DstReg, RegState::Define | DstRegState)
+          .addReg(SrcReg, SrcRegState)
           .addImm(Inst.getImm())
           .setMIFlag(Flag);
       break;
@@ -776,6 +789,7 @@ void RISCVInstrInfo::movImm(MachineBasicBlock &MBB,
 
     // Only the first instruction has X0 as its source.
     SrcReg = DstReg;
+    SrcRenamable = DstRenamable;
   }
 }
 
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.h b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
index 5584e5571c9bc35..5c33c5b6a5a1b2a 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.h
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
@@ -91,7 +91,8 @@ class RISCVInstrInfo : public RISCVGenInstrInfo {
   // Materializes the given integer Val into DstReg.
   void movImm(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
               const DebugLoc &DL, Register DstReg, uint64_t Val,
-              MachineInstr::MIFlag Flag = MachineInstr::NoFlags) const;
+              MachineInstr::MIFlag Flag = MachineInstr::NoFlags,
+              bool DstRenamable = false, bool DstIsDead = false) const;
 
   unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
 
diff --git a/llvm/lib/Target/RISCV/RISCVPostRAExpandPseudoInsts.cpp b/llvm/lib/Target/RISCV/RISCVPostRAExpandPseudoInsts.cpp
index 407e7cfd6fef830..bc9b66d6ca6b114 100644
--- a/llvm/lib/Target/RISCV/RISCVPostRAExpandPseudoInsts.cpp
+++ b/llvm/lib/Target/RISCV/RISCVPostRAExpandPseudoInsts.cpp
@@ -92,52 +92,13 @@ bool RISCVPostRAExpandPseudo::expandMovImm(MachineBasicBlock &MBB,
       Val, MBB.getParent()->getSubtarget().getFeatureBits());
   assert(!Seq.empty());
 
-  Register SrcReg = RISCV::X0;
   Register DstReg = MBBI->getOperand(0).getReg();
   bool DstIsDead = MBBI->getOperand(0).isDead();
   bool Renamable = MBBI->getOperand(0).isRenamable();
-  bool SrcRenamable = false;
-  unsigned Num = 0;
-
-  for (RISCVMatInt::Inst &Inst : Seq) {
-    bool LastItem = ++Num == Seq.size();
-    switch (Inst.getOpndKind()) {
-    case RISCVMatInt::Imm:
-      BuildMI(MBB, MBBI, DL, TII->get(Inst.getOpcode()))
-          .addReg(DstReg, RegState::Define |
-                              getDeadRegState(DstIsDead && LastItem) |
-                              getRenamableRegState(Renamable))
-          .addImm(Inst.getImm());
-      break;
-    case RISCVMatInt::RegX0:
-      BuildMI(MBB, MBBI, DL, TII->get(Inst.getOpcode()))
-          .addReg(DstReg, RegState::Define |
-                              getDeadRegState(DstIsDead && LastItem) |
-                              getRenamableRegState(Renamable))
-          .addReg(SrcReg, RegState::Kill | getRenamableRegState(SrcRenamable))
-          .addReg(RISCV::X0);
-      break;
-    case RISCVMatInt::RegReg:
-      BuildMI(MBB, MBBI, DL, TII->get(Inst.getOpcode()))
-          .addReg(DstReg, RegState::Define |
-                              getDeadRegState(DstIsDead && LastItem) |
-                              getRenamableRegState(Renamable))
-          .addReg(SrcReg, RegState::Kill | getRenamableRegState(SrcRenamable))
-          .addReg(SrcReg, RegState::Kill | getRenamableRegState(SrcRenamable));
-      break;
-    case RISCVMatInt::RegImm:
-      BuildMI(MBB, MBBI, DL, TII->get(Inst.getOpcode()))
-          .addReg(DstReg, RegState::Define |
-                              getDeadRegState(DstIsDead && LastItem) |
-                              getRenamableRegState(Renamable))
-          .addReg(SrcReg, RegState::Kill | getRenamableRegState(SrcRenamable))
-          .addImm(Inst.getImm());
-      break;
-    }
-    // Only the first instruction has X0 as its source.
-    SrcReg = DstReg;
-    SrcRenamable = Renamable;
-  }
+
+  TII->movImm(MBB, MBBI, DL, DstReg, Val, MachineInstr::NoFlags, Renamable,
+              DstIsDead);
+
   MBBI->eraseFromParent();
   return true;
 }

``````````

</details>


https://github.com/llvm/llvm-project/pull/70389