[AArch64ExpandPseudos] Preserve renamable state when expanding MOVi64 & co.

[fhahn]

Summary

If the MOVi operand was renamable, the operands of the expanded
instructions are also renamable.

[thegameg]

llvm/test/CodeGen/AArch64/expand-movi-renamable.mir

2

You should be able to use -run-pass here.

10

You can also get rid of the IR and only keep MIR here.

[fhahn]

Drop IR from MIR test, use run-pass.

[thegameg]

LGTM

llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp

 
 /// Expand a MOVi32imm or MOVi64imm pseudo instruction to one or more
 /// real move-immediate instructions to synthesize the immediate.
 bool AArch64ExpandPseudo::expandMOVImm(MachineBasicBlock &MBB,
                                        MachineBasicBlock::iterator MBBI,
                                        unsigned BitSize) {
   MachineInstr &MI = *MBBI;
   Register DstReg = MI.getOperand(0).getReg();
+  uint64_t RenamableState =
+      MI.getOperand(0).isRenamable() ? RegState::Renamable : 0;
   uint64_t Imm = MI.getOperand(1).getImm();
 
   if (DstReg == AArch64::XZR || DstReg == AArch64::WZR) {
     // Useless def, and we don't want to risk creating an invalid ORR (which
     // would really write to sp).
     MI.eraseFromParent();
     return true;
   }
case AArch64::ORRXri:
       break;
     case AArch64::MOVNWi:
     case AArch64::MOVNXi:
     case AArch64::MOVZWi:
     case AArch64::MOVZXi: {
       bool DstIsDead = MI.getOperand(0).isDead();
       MIBS.push_back(BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(I->Opcode))
         .addReg(DstReg, RegState::Define |
-                getDeadRegState(DstIsDead && LastItem))
+                getDeadRegState(DstIsDead && LastItem) |
+                RenamableState)
         .addImm(I->Op1)
         .addImm(I->Op2));
       } break;
     case AArch64::MOVKWi:
     case AArch64::MOVKXi: {
       Register DstReg = MI.getOperand(0).getReg();
       bool DstIsDead = MI.getOperand(0).isDead();
       MIBS.push_back(BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(I->Opcode))
         .addReg(DstReg,
                 RegState::Define |
-                getDeadRegState(DstIsDead && LastItem))
+                getDeadRegState(DstIsDead && LastItem) |
+                RenamableState)
         .addReg(DstReg)
         .addImm(I->Op1)
         .addImm(I->Op2));
       } break;
     }
   }
   transferImpOps(MI, MIBS.front(), MIBS.back());
   MI.eraseFromParent();

llvm/test/CodeGen/AArch64/expand-movi-renamable.mir

+# RUN: llc -run-pass=aarch64-expand-pseudo -mtriple=arm64-apple-darwin -o - %s | FileCheck %s
+
+# Check that we preserve renamble when expanding MOVi32imm/MOVi64imm.
+#
+---
+# CHECK-LABEL:  name: test_i32
+# CHECK-LABEL:  bb.0:
+# CHECK-NEXT:     $sp = frame-setup SUBXri $sp, 32, 0
+# CHECK-NEXT:     renamable $w8 = MOVZWi 4, 0
+# CHECK-NEXT:     STRWui killed renamable $w8, $sp, 0
+# CHECK-NEXT:     $w8 = MOVZWi 45926, 0
+# CHECK-NEXT:     $w8 = MOVKWi $w8, 102, 16
+# CHECK-NEXT:     STRWui killed renamable $w8, $sp, 1
+# CHECK-NEXT:     renamable $w8 = MOVZWi 10319, 0
+# CHECK-NEXT:     renamable $w8 = MOVKWi $w8, 2942, 16
+# CHECK-NEXT:     STRWui killed renamable $w8, $sp, 2
+# CHECK-NEXT:     renamable $w8 = MOVZWi 30600, 0
+# CHECK-NEXT:     renamable $w8 = MOVKWi $w8, 21862, 16
+# CHECK-NEXT:     STRWui killed renamable $w8, $sp, 3
+# CHECK-NEXT:     $sp = frame-destroy ADDXri $sp, 32, 0
+# CHECK-NEXT:     RET undef $lr
+#
+name:           test_i32
+alignment:       8
+tracksRegLiveness: true
+frameInfo:
+  stackSize:       32
+  maxAlignment:    4
+  maxCallFrameSize: 0
+  localFrameSize:  24
+stack:
+  - { id: 0, offset: -4, size: 4, alignment: 4, local-offset: -4 }
+  - { id: 1, offset: -8, size: 4, alignment: 4, local-offset: -8 }
+  - { id: 2, offset: -12, size: 4, alignment: 4, local-offset: -12 }
+  - { id: 3, offset: -16, size: 4, alignment: 4, local-offset: -16 }
+machineFunctionInfo: {}
+body:             |
+  bb.0:
+    $sp = frame-setup SUBXri $sp, 32, 0
+    renamable $w8 = MOVi32imm 4
+    STRWui killed renamable $w8, $sp, 0
+    $w8 = MOVi32imm 6730598
+    STRWui killed renamable $w8, $sp, 1
+    renamable $w8 = MOVi32imm 192817231
+    STRWui killed renamable $w8, $sp, 2
+    renamable $w8 = MOVi32imm 1234605616436508552
+    STRWui killed renamable $w8, $sp, 3
+    $sp = frame-destroy ADDXri $sp, 32, 0
+    RET_ReallyLR
+
+...
+---
+# CHECK-LABEL:  name: test_i64
+# CHECK-LABEL:  bb.0:
+# CHECK-NEXT:     $sp = frame-setup SUBXri $sp, 32, 0
+# CHECK-NEXT:     renamable $x8 = MOVZXi 4, 0
+# CHECK-NEXT:     STRXui killed renamable $x8, $sp, 0
+# CHECK-NEXT:     $x8 = MOVZXi 45926, 0
+# CHECK-NEXT:     $x8 = MOVKXi $x8, 102, 16
+# CHECK-NEXT:     STRXui killed renamable $x8, $sp, 1
+# CHECK-NEXT:     renamable $x8 = MOVNXi 25166, 0
+# CHECK-NEXT:     renamable $x8 = MOVKXi $x8, 55686, 16
+# CHECK-NEXT:     renamable $x8 = MOVKXi $x8, 63160, 32
+# CHECK-NEXT:     STRXui killed renamable $x8, $sp, 2
+# CHECK-NEXT:     renamable $x8 = MOVZXi 30600, 0
+# CHECK-NEXT:     renamable $x8 = MOVKXi $x8, 21862, 16
+# CHECK-NEXT:     renamable $x8 = MOVKXi $x8, 13124, 32
+# CHECK-NEXT:     renamable $x8 = MOVKXi $x8, 4386, 48
+# CHECK-NEXT:     STRXui killed renamable $x8, $sp, 3
+# CHECK-NEXT:     $sp = frame-destroy ADDXri $sp, 32, 0
+# CHECK-NEXT:     RET undef $lr
+#
+name:           test_i64
+alignment:       8
+tracksRegLiveness: true
+frameInfo:
+  stackSize:       32
+  maxAlignment:    4
+  maxCallFrameSize: 0
+  localFrameSize:  32
+stack:
+  - { id: 0, offset: -8, size: 8, alignment: 4, local-offset: -8 }
+  - { id: 1, offset: -16, size: 8, alignment: 4, local-offset: -16 }
+  - { id: 2, offset: -24, size: 8, alignment: 4, local-offset: -24}
+  - { id: 3, offset: -32, size: 8, alignment: 4, local-offset: -32 }
+machineFunctionInfo: {}
+body:             |
+  bb.0:
+    $sp = frame-setup SUBXri $sp, 32, 0
+    renamable $x8 = MOVi64imm 4
+    STRXui killed renamable $x8, $sp, 0
+    $x8 = MOVi64imm 6730598
+    STRXui killed renamable $x8, $sp, 1
+    renamable $x8 = MOVi64imm -10201192817231
+    STRXui killed renamable $x8, $sp, 2
+    renamable $x8 = MOVi64imm 1234605616436508552
+    STRXui killed renamable $x8, $sp, 3
+    $sp = frame-destroy ADDXri $sp, 32, 0
+    RET_ReallyLR
+
+...
+---