Mercurial > hg > CbC > CbC_llvm
view clang/test/CodeGen/2008-01-25-ByValReadNone.c @ 207:2e18cbf3894f
LLVM12
author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
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date | Tue, 08 Jun 2021 06:07:14 +0900 |
parents | 1d019706d866 |
children |
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// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -o - %s | FileCheck %s // It could hit in @llvm.memcpy with "-triple x86_64-(mingw32|win32)". // CHECK-NOT: readonly // CHECK-NOT: readnone // The struct being passed byval means that we cannot mark the // function readnone. Readnone would allow stores to the arg to // be deleted in the caller. We also don't allow readonly since // the callee might write to the byval parameter. The inliner // would have to assume the worse and introduce an explicit // temporary when inlining such a function, which is costly for // the common case in which the byval argument is not written. struct S { int A[1000]; }; int __attribute__ ((const)) f(struct S x) { x.A[1] = 0; return x.A[0]; } int g(struct S x) __attribute__ ((pure)); int h(struct S x) { return g(x); }