https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63365
Bug ID: 63365
Summary: [ARM] Incorrect copy propagation for vclz intrinsic
Product: gcc
Version: 4.9.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: michael.collison at linaro dot org
Created attachment 33558
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33558&action=edit
Test case demonstrating incorrect code generation for vclz
Compiling and executing the attached testcase at -O2 produces incorrect code
and execution results. Instead of code being generated for the vclz instruction
the compiler propagates an incorrect constant value for what it believes will
be the result of the instruction. The attached test case is part of a proposed
set of DejaGnu tests for neon intrinsics.
------------------------------------------------------------------------------
Target: arm-linux-gnueabihf
Configured with:
'/home/michael-collison/neon-intrinsic-build/snapshots/gcc.git~neon-intrinsic-christophe/configure'
--with-bugurl=https://bugs.launchpad.net/gcc-linaro
--with-mpc=/home/michael-collison/neon-intrinsic-build/builds/destdir/x86_64-unknown-linux-gnu
--with-mpfr=/home/michael-collison/neon-intrinsic-build/builds/destdir/x86_64-unknown-linux-gnu
--with-gmp=/home/michael-collison/neon-intrinsic-build/builds/destdir/x86_64-unknown-linux-gnu
--with-gnu-as --with-gnu-ld --disable-libstdcxx-pch --disable-libmudflap
--with-cloog=no --with-ppl=no --with-isl=no --disable-nls --enable-multiarch
--disable-multilib --enable-c99 --with-arch=armv7-a --with-fpu=vfpv3-d16
--with-float=hard --with-mode=thumb
--with-sysroot=/opt/linaro/sysroot-linaro_eglibc-2_19-arm-clean-linux-gnueabihf
--with-build-sysroot=/home/michael-collison/neon-intrinsic-build/sysroots/arm-clean-linux-gnueabihf
--enable-lto --enable-linker-build-id --enable-long-long
--enable-languages=c,c++,fortran,go,lto
--with-bugurl=https://bugs.launchpad.net/gcc-linaro --with-pkgversion='Linaro
GCC 2014.08' --build=x86_64-unknown-linux-gnu --host=x86_64-unknown-linux-gnu
--target=arm-clean-linux-gnueabihf
--prefix=/home/michael-collison/neon-intrinsic-build/builds/destdir/x86_64-unknown-linux-gnu
Thread model: posix
gcc version 4.10.0 20140812 (experimental) (Linaro GCC 2014.08)
