__builtin_expect() not recognized within an OpenMP section

Originator:arthur.j.odwyer
Number:rdar://13775441 Date Originated:30-Apr-2013 12:57 PM
Status:Closed Resolved:WONTFIX
Product:Developer Tools Product Version:gcc 4.2.1 (5658) (LLVM 2336.11.00)
Classification:Serious Bug Reproducible:Always
 
Summary: A trivial program fails to link properly with -fopenmp. llvm-gcc doesn't recognize __builtin_expect() inside an OpenMP section.

Steps to Reproduce: Cut and paste into a terminal window. I'm using OSX 10.8.2 and llvm-gcc 4.2.1.

cat >test.c <<EOF
#include <assert.h>
int foo() { return 1; }
int main() {
    #pragma omp parallel
    assert(foo());
}
EOF
gcc -fopenmp test.c


Expected Results: The program should link correctly.

Actual Results: llvm-gcc produces a linker error.

Undefined symbols for architecture x86_64:
  "___builtin_expect", referenced from:
      _main.omp_fn.0 in ccJY6t0O.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status

Regression:

Notes: This has been reported many other places on the Web, but I cannot find a public bug report about it, nor do I see any public admission that Apple knows about this bug; therefore I'm filing a new bug report about it.

I've attached "gcc-v.txt", the output of "gcc -fopenmp test.c -v".

As of 2013-04-30, Clang doesn't support OpenMP at all; so using Clang is not a workaround.

30-Apr-2013 12:57 PM Arthur O'Dwyer:
'gcc-v.txt' was successfully uploaded

Comments

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By arthur.j.odwyer at May 8, 2013, 5:53 p.m. (reply...)

contents of "gcc-v.txt"

Using built-in specs.
Target: i686-apple-darwin11
Configured with: /private/var/tmp/llvmgcc42/llvmgcc42-2336.11~67/src/configure --disable-checking --enable-werror --prefix=/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2 --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-prefix=llvm- --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin11 --enable-llvm=/private/var/tmp/llvmgcc42/llvmgcc42-2336.11~67/dst-llvmCore/Developer/usr/local --program-prefix=i686-apple-darwin11- --host=x86_64-apple-darwin11 --target=i686-apple-darwin11 --with-gxx-include-dir=/usr/include/c++/4.2.1
Thread model: posix
gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00)
 /usr/llvm-gcc-4.2/bin/../libexec/gcc/i686-apple-darwin11/4.2.1/cc1 -quiet -v -imultilib x86_64 -iprefix /usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/ -D__DYNAMIC__ test.c -fPIC -quiet -dumpbase test.c -mmacosx-version-min=10.8.2 -m64 -mtune=core2 -auxbase test -version -fopenmp -o /var/folders/1z/jvnkrdws621c6wmrcf7q_9180000gn/T//ccFVPmhX.s
ignoring nonexistent directory "/usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/../../../../i686-apple-darwin11/include"
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/../../../../i686-apple-darwin11/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/include
 /usr/local/include
 /Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.
GNU C version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00) (i686-apple-darwin11)
    compiled by GNU C version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00).
GGC heuristics: --param ggc-min-expand=150 --param ggc-min-heapsize=131072
Compiler executable checksum: 63f837dac9420982bb89d90674491a57
 /usr/llvm-gcc-4.2/bin/../libexec/gcc/i686-apple-darwin11/4.2.1/as -arch x86_64 -force_cpusubtype_ALL -o /var/folders/1z/jvnkrdws621c6wmrcf7q_9180000gn/T//ccj7ftP5.o /var/folders/1z/jvnkrdws621c6wmrcf7q_9180000gn/T//ccFVPmhX.s
Reading specs from /usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/libgomp.spec
 /usr/llvm-gcc-4.2/bin/../libexec/gcc/i686-apple-darwin11/4.2.1/collect2 -dynamic -arch x86_64 -macosx_version_min 10.8.2 -weak_reference_mismatches non-weak -o a.out -lcrt1.10.6.o -lgomp -L/usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/x86_64 -L/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/x86_64 -L/usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1 -L/usr/llvm-gcc-4.2/bin/../lib/gcc -L/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1 -L/usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/../../.. -L/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/../../.. /var/folders/1z/jvnkrdws621c6wmrcf7q_9180000gn/T//ccj7ftP5.o -lSystem -lgcc -lSystem
Undefined symbols for architecture x86_64:
  "___builtin_expect", referenced from:
      _main.omp_fn.0 in ccj7ftP5.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status
By arthur.j.odwyer at April 30, 2013, 8:01 p.m. (reply...)

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