[llvm] [RISCV] Check EnsureWholeVectorRegisterMoveValidVTYPE in RISCVInsertVSETVLI::transferBefore. (PR #190022)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

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

Author: Craig Topper (topperc)

<details>
<summary>Changes</summary>

Fixes #<!-- -->189786

---
Full diff: https://github.com/llvm/llvm-project/pull/190022.diff


2 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp (+2-1) 
- (added) llvm/test/CodeGen/RISCV/rvv/vsetvli-insert-whole-reg-move.ll (+27) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp b/llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
index 2569954d62eb0..8a5ac3363b905 100644
--- a/llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
+++ b/llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
@@ -314,7 +314,8 @@ static VSETVLIInfo adjustIncoming(const VSETVLIInfo &PrevInfo,
 // legal for MI, but may not be the state requested by MI.
 void RISCVInsertVSETVLI::transferBefore(VSETVLIInfo &Info,
                                         const MachineInstr &MI) const {
-  if (RISCV::isVectorCopy(ST->getRegisterInfo(), MI) &&
+  if (EnsureWholeVectorRegisterMoveValidVTYPE &&
+      RISCV::isVectorCopy(ST->getRegisterInfo(), MI) &&
       (Info.isUnknown() || !Info.isValid() || Info.hasSEWLMULRatioOnly())) {
     // Use an arbitrary but valid AVL and VTYPE so vill will be cleared. It may
     // be coalesced into another vsetvli since we won't demand any fields.
diff --git a/llvm/test/CodeGen/RISCV/rvv/vsetvli-insert-whole-reg-move.ll b/llvm/test/CodeGen/RISCV/rvv/vsetvli-insert-whole-reg-move.ll
new file mode 100644
index 0000000000000..9e77ef3c85462
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/rvv/vsetvli-insert-whole-reg-move.ll
@@ -0,0 +1,27 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6
+; RUN: llc < %s -mtriple=riscv64 -mattr=+v | FileCheck %s --check-prefix=ENABLE
+; RUN: llc < %s -mtriple=riscv64 -mattr=+v -riscv-insert-vsetvli-whole-vector-register-move-valid-vtype=false | FileCheck %s --check-prefix=DISABLE
+
+define <vscale x 8 x i8>  @foo(<vscale x 8 x i8> %0, <vscale x 8 x i8> %1, <vscale x 8 x i8> %2) nounwind {
+; ENABLE-LABEL: foo:
+; ENABLE:       # %bb.0: # %entry
+; ENABLE-NEXT:    vsetivli zero, 1, e8, m1, ta, ma
+; ENABLE-NEXT:    vmv1r.v v8, v9
+; ENABLE-NEXT:    vmadd.vv v8, v9, v9
+; ENABLE-NEXT:    ret
+;
+; DISABLE-LABEL: foo:
+; DISABLE:       # %bb.0: # %entry
+; DISABLE-NEXT:    vmv1r.v v8, v9
+; DISABLE-NEXT:    vsetivli zero, 1, e8, m1, ta, ma
+; DISABLE-NEXT:    vmadd.vv v8, v9, v9
+; DISABLE-NEXT:    ret
+entry:
+  %a = call <vscale x 8 x i8> @llvm.riscv.vmadd.nxv8i8.nxv8i8(
+    <vscale x 8 x i8> %1,
+    <vscale x 8 x i8> %1,
+    <vscale x 8 x i8> %1,
+    i64 1, i64 1)
+
+  ret <vscale x 8 x i8> %a
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/190022