[llvm-branch-commits] [llvm] release/19.x: [AArch64] Avoid inlining if ZT0 needs preserving. (#101343) (PR #101932)

[via llvm-branch-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: None (llvmbot)

<details>
<summary>Changes</summary>

Backport fb470db7b3a8ce6853e8bf17d235617a2fa79434

Requested by: @<!-- -->sdesmalen-arm

---
Full diff: https://github.com/llvm/llvm-project/pull/101932.diff


2 Files Affected:

- (modified) llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp (+2-1) 
- (modified) llvm/test/Transforms/Inline/AArch64/sme-pstateza-attrs.ll (+45) 


``````````diff
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index 45148449dfb82..9630b36b99348 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -254,7 +254,8 @@ bool AArch64TTIImpl::areInlineCompatible(const Function *Caller,
     return false;
 
   if (CallerAttrs.requiresLazySave(CalleeAttrs) ||
-      CallerAttrs.requiresSMChange(CalleeAttrs)) {
+      CallerAttrs.requiresSMChange(CalleeAttrs) ||
+      CallerAttrs.requiresPreservingZT0(CalleeAttrs)) {
     if (hasPossibleIncompatibleOps(Callee))
       return false;
   }
diff --git a/llvm/test/Transforms/Inline/AArch64/sme-pstateza-attrs.ll b/llvm/test/Transforms/Inline/AArch64/sme-pstateza-attrs.ll
index 816492768cc0f..5e638103a2b06 100644
--- a/llvm/test/Transforms/Inline/AArch64/sme-pstateza-attrs.ll
+++ b/llvm/test/Transforms/Inline/AArch64/sme-pstateza-attrs.ll
@@ -231,6 +231,51 @@ define void @shared_za_caller_private_za_callee_call_tpidr2_restore_dont_inline(
   ret void
 }
 
+define void @nonzt0_callee() {
+; CHECK-LABEL: define void @nonzt0_callee
+; CHECK-SAME: () #[[ATTR0]] {
+; CHECK-NEXT:    call void asm sideeffect "
+; CHECK-NEXT:    call void @inlined_body()
+; CHECK-NEXT:    ret void
+;
+  call void asm sideeffect "; inlineasm", ""()
+  call void @inlined_body()
+  ret void
+}
+
+define void @shared_zt0_caller_nonzt0_callee_dont_inline() "aarch64_inout_zt0" {
+; CHECK-LABEL: define void @shared_zt0_caller_nonzt0_callee_dont_inline
+; CHECK-SAME: () #[[ATTR3:[0-9]+]] {
+; CHECK-NEXT:    call void @nonzt0_callee()
+; CHECK-NEXT:    ret void
+;
+  call void @nonzt0_callee()
+  ret void
+}
+
+define void @shared_zt0_callee() "aarch64_inout_zt0" {
+; CHECK-LABEL: define void @shared_zt0_callee
+; CHECK-SAME: () #[[ATTR3]] {
+; CHECK-NEXT:    call void asm sideeffect "
+; CHECK-NEXT:    call void @inlined_body()
+; CHECK-NEXT:    ret void
+;
+  call void asm sideeffect "; inlineasm", ""()
+  call void @inlined_body()
+  ret void
+}
+
+define void @shared_zt0_caller_shared_zt0_callee_inline() "aarch64_inout_zt0" {
+; CHECK-LABEL: define void @shared_zt0_caller_shared_zt0_callee_inline
+; CHECK-SAME: () #[[ATTR3]] {
+; CHECK-NEXT:    call void asm sideeffect "
+; CHECK-NEXT:    call void @inlined_body()
+; CHECK-NEXT:    ret void
+;
+  call void @shared_zt0_callee()
+  ret void
+}
+
 declare void @__arm_za_disable()
 declare void @__arm_tpidr2_save()
 declare void @__arm_tpidr2_restore(ptr)

``````````

</details>


https://github.com/llvm/llvm-project/pull/101932