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author | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2014-03-10 23:42:28 +0000 |
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committer | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2014-03-10 23:42:28 +0000 |
commit | f5d17528ee24cfd3f77a4b11b82486a5a9a6d920 (patch) | |
tree | da650c71822c517b09ea70c47183061f6fb5c424 /test/LTO/no-undefined-puts-when-implemented.ll | |
parent | 6df2b690989f499965640305b2045142192eca74 (diff) | |
download | llvm-f5d17528ee24cfd3f77a4b11b82486a5a9a6d920.tar.gz llvm-f5d17528ee24cfd3f77a4b11b82486a5a9a6d920.tar.bz2 llvm-f5d17528ee24cfd3f77a4b11b82486a5a9a6d920.tar.xz |
Module: Don't rename in getOrInsertFunction()
During LTO, user-supplied definitions of C library functions often
exist. -instcombine uses Module::getOrInsertFunction() to get a handle
on library functions (e.g., @puts, when optimizing @printf).
Previously, Module::getOrInsertFunction() would rename any matching
functions with local linkage, and create a new declaration. In LTO,
this is the opposite of desired behaviour, as it skips by the
user-supplied version of the library function and creates a new
undefined reference which the linker often cannot resolve.
After some discussing with Rafael on the list, it looks like it's
undesired behaviour. If a consumer actually *needs* this behaviour, we
should add new API with a more explicit name.
I added two testcases: one specifically for the -instcombine behaviour
and one for the LTO flow.
<rdar://problem/16165191>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203513 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/LTO/no-undefined-puts-when-implemented.ll')
-rw-r--r-- | test/LTO/no-undefined-puts-when-implemented.ll | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/test/LTO/no-undefined-puts-when-implemented.ll b/test/LTO/no-undefined-puts-when-implemented.ll new file mode 100644 index 0000000000..18f5d21481 --- /dev/null +++ b/test/LTO/no-undefined-puts-when-implemented.ll @@ -0,0 +1,40 @@ +; RUN: llvm-as <%s >%t1 +; RUN: llvm-lto -exported-symbol=_uses_puts -exported-symbol=_uses_printf -o - %t1 | \ +; RUN: llvm-nm | \ +; RUN: FileCheck %s +; rdar://problem/16165191 +; runtime library implementations should not be renamed + +target triple = "x86_64-apple-darwin11" + +@str = private unnamed_addr constant [13 x i8] c"hello world\0A\00" + +; CHECK-NOT: U _puts +; CHECK: T _uses_printf +; CHECK: T _uses_puts +define i32 @uses_puts(i32 %i) { +entry: + %s = call i8* @foo(i32 %i) + %ret = call i32 @puts(i8* %s) + ret i32 %ret +} +define i32 @uses_printf(i32 %i) { +entry: + %s = getelementptr [13 x i8]* @str, i64 0, i64 0 + call i32 (i8*, ...)* @printf(i8* %s) + ret i32 0 +} + +define hidden i32 @printf(i8* readonly nocapture %fmt, ...) { +entry: + %ret = call i32 @bar(i8* %fmt) + ret i32 %ret +} +define hidden i32 @puts(i8* %s) { +entry: + %ret = call i32 @bar(i8* %s) + ret i32 %ret +} + +declare i8* @foo(i32) +declare i32 @bar(i8*) |