maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/clang/test/CodeGen/asm-attrs.c

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

34 lines
1.2 KiB
C
Raw Normal View History

[inlineasm] Attach readonly and readnone to inline-asm instructions. Previously, clang/llvm treated inline-asm instructions conservatively, choosing not to eliminate the instructions or hoisting them out of a loop even when it was safe to do so. This commit makes changes to attach a readonly or readnone attribute to an inline-asm instruction, which enables passes such as LICM and EarlyCSE to move or optimize away the instruction. rdar://problem/11358192 Differential Revision: http://reviews.llvm.org/D10546 llvm-svn: 241930
2015-07-11 02:44:40 +08:00
// RUN: %clang_cc1 -triple armv7-apple-darwin -emit-llvm %s -o - | FileCheck %s
// CHECK: call i32 asm "foo0", {{.*}} [[READNONE:#[0-9]+]]
// CHECK: call i32 asm "foo1", {{.*}} [[READNONE]]
// CHECK: call i32 asm "foo2", {{.*}} [[NOATTRS:#[0-9]+]]
// CHECK: call i32 asm sideeffect "foo3", {{.*}} [[NOATTRS]]
// CHECK: call i32 asm "foo4", {{.*}} [[READONLY:#[0-9]+]]
// CHECK: call i32 asm "foo5", {{.*}} [[READONLY]]
// CHECK: call i32 asm "foo6", {{.*}} [[NOATTRS]]
// CHECK: call void asm sideeffect "foo7", {{.*}} [[NOATTRS]]
[CodeGen]: don't treat structures returned in registers as memory inputs Summary: The "=r" output constraint for a structure variable passed to inline asm shouldn't be converted to "=*r", as this changes the asm directive semantics and prevents DSE optimizations. Instead, preserve the constraints and return such structures as integers of corresponding size, which are converted back to structures when storing the result. Fixes PR42672. Subscribers: cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D65234 llvm-svn: 370335
2019-08-29 19:21:41 +08:00
// CHECK: call i32 asm "foo8", {{.*}} [[READNONE]]
[inlineasm] Attach readonly and readnone to inline-asm instructions. Previously, clang/llvm treated inline-asm instructions conservatively, choosing not to eliminate the instructions or hoisting them out of a loop even when it was safe to do so. This commit makes changes to attach a readonly or readnone attribute to an inline-asm instruction, which enables passes such as LICM and EarlyCSE to move or optimize away the instruction. rdar://problem/11358192 Differential Revision: http://reviews.llvm.org/D10546 llvm-svn: 241930
2015-07-11 02:44:40 +08:00
// CHECK: attributes [[READNONE]] = { nounwind readnone }
// CHECK: attributes [[NOATTRS]] = { nounwind }
// CHECK: attributes [[READONLY]] = { nounwind readonly }
int g0, g1;
struct S {
int i;
} g2;
void test_attrs(int a) {
__asm__ ("foo0" : "=r"(g1) : "r"(a));
__asm__ ("foo1" : "=r"(g1) : "r"(a) : "cc");
__asm__ ("foo2" : "=r"(g1) : "r"(a) : "memory");
__asm__ volatile("foo3" : "=r"(g1) : "r"(a));
__asm__ ("foo4" : "=r"(g1) : "r"(a), "m"(g0));
__asm__ ("foo5" : "=r"(g1) : "r"(a), "Q"(g0));
__asm__ ("foo6" : "=r"(g1), "=m"(g0) : "r"(a));
__asm__ ("foo7" : : "r"(a));
__asm__ ("foo8" : "=r"(g2) : "r"(a));
}