[clang] [llvm] New calling convention preserve_none (PR #76868)

[David Li via cfe-commits]

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@@ -0,0 +1,85 @@
+; RUN: llc < %s -mtriple=x86_64-apple-darwin -mcpu=corei7     | FileCheck --check-prefixes=ALL %s
+; RUN: llc < %s -mtriple=x86_64-apple-darwin -mcpu=corei7-avx | FileCheck --check-prefixes=ALL,AVX %s
+
+; Don't need to preserve registers before using them.
+define preserve_nonecc double @preserve_nonecc1() nounwind {
+entry:
+;ALL-LABEL:   preserve_nonecc1
+;ALL-NOT:     movaps %xmm1
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david-xl wrote:

check no savings of GSRs too?

https://github.com/llvm/llvm-project/pull/76868