[PATCH] D128062: [PowerPC] Fix PPCVSXSwapRemoval pass to include MTVSCR and MFVSCR as not swappable.

[Quinn Pham via Phabricator via llvm-commits]

quinnp created this revision.
Herald added subscribers: shchenz, kbarton, hiraditya, nemanjai.
Herald added a project: All.
quinnp requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

This patch adds the instructions `MTVSCR` and `MFVSCR` as not swappable to the
PPCVSXSwapRemoval pass because they are not lane-insensitive. This will prevent
the compiler from optimizing out required swaps when using `lxvd2x` and
`stxvd2x`.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D128062

Files:
  llvm/lib/Target/PowerPC/PPCVSXSwapRemoval.cpp
  llvm/test/CodeGen/PowerPC/mtvsrc-mfvscr-PPCVSXSwapRemoval.ll


Index: llvm/test/CodeGen/PowerPC/mtvsrc-mfvscr-PPCVSXSwapRemoval.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/PowerPC/mtvsrc-mfvscr-PPCVSXSwapRemoval.ll
@@ -0,0 +1,37 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-unknown-unknown \
+; RUN:   -mcpu=pwr8 -O2 < %s | FileCheck %s
+
+define void @test_mtvscr() {
+; CHECK-LABEL: test_mtvscr:
+; CHECK:       # %bb.0: # %test_mtvscr_entry
+; CHECK-NEXT:    addi 3, 1, -16
+; CHECK-NEXT:    lxvd2x 0, 0, 3
+; CHECK-NEXT:    xxswapd 34, 0
+; CHECK-NEXT:    mtvscr 2
+; CHECK-NEXT:    blr
+test_mtvscr_entry:
+  %0 = alloca <4 x i32>
+  %1 = load <4 x i32>, <4 x i32>* %0
+  call void @llvm.ppc.altivec.mtvscr(<4 x i32> %1)
+  ret void
+}
+
+define void @test_mfvscr() {
+; CHECK-LABEL: test_mfvscr:
+; CHECK:       # %bb.0: # %test_mfvscr_entry
+; CHECK-NEXT:    mfvscr 2
+; CHECK-NEXT:    addi 3, 1, -16
+; CHECK-NEXT:    xxswapd 0, 34
+; CHECK-NEXT:    stxvd2x 0, 0, 3
+; CHECK-NEXT:    blr
+test_mfvscr_entry:
+  %0 = alloca <8 x i16>
+  %1 = call <8 x i16> @llvm.ppc.altivec.mfvscr()
+  store <8 x i16> %1, <8 x i16>* %0
+  ret void
+}
+
+declare void @llvm.ppc.altivec.mtvscr(<4 x i32>)
+
+declare <8 x i16> @llvm.ppc.altivec.mfvscr()
Index: llvm/lib/Target/PowerPC/PPCVSXSwapRemoval.cpp
===================================================================
--- llvm/lib/Target/PowerPC/PPCVSXSwapRemoval.cpp
+++ llvm/lib/Target/PowerPC/PPCVSXSwapRemoval.cpp
@@ -519,6 +519,8 @@
       case PPC::XXSLDWI:
       case PPC::XSCVDPSPN:
       case PPC::XSCVSPDPN:
+      case PPC::MTVSCR:
+      case PPC::MFVSCR:
         break;
       }
     }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D128062.437903.patch
Type: text/x-patch
Size: 1740 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220617/6a0afc66/attachment.bin>