[PATCH] D117429: [AArch64] Revive optimize add/sub with immediate through MIPeepholeOpt

[Micah Weston via Phabricator via llvm-commits]

red1bluelost updated this revision to Diff 401225.
red1bluelost added a comment.

Adds a test to catch the bug earlier and then fixes the issue.

The issue was related to differing register classes between the rr and ri
versions of the instructions.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D117429/new/

https://reviews.llvm.org/D117429

Files:
  llvm/lib/Target/AArch64/AArch64MIPeepholeOpt.cpp
  llvm/test/CodeGen/AArch64/addsub-24bit-imm.mir


Index: llvm/test/CodeGen/AArch64/addsub-24bit-imm.mir
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AArch64/addsub-24bit-imm.mir
@@ -0,0 +1,63 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -run-pass=aarch64-mi-peephole-opt -o - -mtriple=aarch64-unknown-linux -verify-machineinstrs %s | FileCheck %s
+
+# Main intention is to verify machine instructions have valid register classes.
+# Use of UBFM[W|X]ri is used as an arbitrary instruction that requires GPR[32|64]RegClass.
+# If the ADD/SUB optimization generates invalid register classes, this test will fail.
+---
+name: addi
+body: |
+  bb.0.entry:
+    liveins: $w0
+    ; CHECK-LABEL: name: addi
+    ; CHECK: [[COPY:%[0-9]+]]:gpr32common = COPY $w0
+    ; CHECK-NEXT: [[ADDWri:%[0-9]+]]:gpr32common = ADDWri [[COPY]], 273, 12
+    ; CHECK-NEXT: [[ADDWri1:%[0-9]+]]:gpr32common = ADDWri [[ADDWri]], 3549, 0
+    ; CHECK-NEXT: [[UBFMWri:%[0-9]+]]:gpr32 = UBFMWri [[ADDWri1]], 28, 31
+    ; CHECK-NEXT: $w0 = COPY [[UBFMWri]]
+    ; CHECK-NEXT: RET_ReallyLR implicit $w0
+    %0:gpr32 = COPY $w0
+    %1:gpr32 = MOVi32imm 1121757
+    %2:gpr32 = ADDWrr %0, %1
+    %3:gpr32 = UBFMWri %2, 28, 31
+    $w0 = COPY %3
+    RET_ReallyLR implicit $w0
+...
+---
+name: addl
+body: |
+  bb.0.entry:
+    liveins: $x0
+    ; CHECK-LABEL: name: addl
+    ; CHECK: [[COPY:%[0-9]+]]:gpr64common = COPY $x0
+    ; CHECK-NEXT: [[ADDXri:%[0-9]+]]:gpr64common = ADDXri [[COPY]], 273, 12
+    ; CHECK-NEXT: [[ADDXri1:%[0-9]+]]:gpr64common = ADDXri [[ADDXri]], 3549, 0
+    ; CHECK-NEXT: [[UBFMXri:%[0-9]+]]:gpr64 = UBFMXri [[ADDXri1]], 28, 31
+    ; CHECK-NEXT: $x0 = COPY [[UBFMXri]]
+    ; CHECK-NEXT: RET_ReallyLR implicit $x0
+    %0:gpr64 = COPY $x0
+    %1:gpr32 = MOVi32imm 1121757
+    %2:gpr64 = SUBREG_TO_REG 0, %1, %subreg.sub_32
+    %3:gpr64 = ADDXrr %0, killed %2
+    %4:gpr64 = UBFMXri %3, 28, 31
+    $x0 = COPY %4
+    RET_ReallyLR implicit $x0
+...
+---
+name: addl_negate
+body: |
+  bb.0.entry:
+    liveins: $x0
+    ; CHECK-LABEL: name: addl_negate
+    ; CHECK: [[COPY:%[0-9]+]]:gpr64common = COPY $x0
+    ; CHECK-NEXT: [[SUBXri:%[0-9]+]]:gpr64common = SUBXri [[COPY]], 273, 12
+    ; CHECK-NEXT: [[SUBXri1:%[0-9]+]]:gpr64common = SUBXri [[SUBXri]], 3549, 0
+    ; CHECK-NEXT: [[UBFMXri:%[0-9]+]]:gpr64 = UBFMXri [[SUBXri1]], 28, 31
+    ; CHECK-NEXT: $x0 = COPY [[UBFMXri]]
+    ; CHECK-NEXT: RET_ReallyLR implicit $x0
+    %0:gpr64 = COPY $x0
+    %1:gpr64 = MOVi64imm -1121757
+    %2:gpr64 = ADDXrr %0, killed %1
+    %3:gpr64 = UBFMXri %2, 28, 31
+    $x0 = COPY %3
+    RET_ReallyLR implicit $x0
Index: llvm/lib/Target/AArch64/AArch64MIPeepholeOpt.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64MIPeepholeOpt.cpp
+++ llvm/lib/Target/AArch64/AArch64MIPeepholeOpt.cpp
@@ -304,8 +304,9 @@
   // Create new ADD/SUB MIs.
   DebugLoc DL = MI.getDebugLoc();
   MachineBasicBlock *MBB = MI.getParent();
-  const TargetRegisterClass *RC =
-      (RegSize == 32) ? &AArch64::GPR32spRegClass : &AArch64::GPR64spRegClass;
+  const TargetRegisterClass *RC = (RegSize == 32)
+                                      ? &AArch64::GPR32commonRegClass
+                                      : &AArch64::GPR64commonRegClass;
   Register DstReg = MI.getOperand(0).getReg();
   Register SrcReg = MI.getOperand(1).getReg();
   Register NewTmpReg = MRI->createVirtualRegister(RC);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D117429.401225.patch
Type: text/x-patch
Size: 3490 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220119/6e9cc7f9/attachment.bin>