http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54252
Bug #: 54252
Summary: [Neon] Bad alignment code generated for Neon loads
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: target
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: eric.ba...@allegorithmic.com
Created attachment 28009
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28009
Small repro case
Using gcc trunk at rev 190381, compiled with the Android NDK r8b build-gcc.sh
script (so an arm-linux-androideabi target) and the command line below, the
attached repro case does not compile, and spits the following error messages:
Erics-Mac:src batut$
/Users/batut/android-ndk-r8b/toolchains/arm-linux-androideabi-4.8.0/prebuilt/darwin-x86/bin/arm-linux-androideabi-gcc
-mfloat-abi=hard -mfpu=vfp -mfpu=neon -marm -O1 -c test.c
/var/folders/nr/l7qlwr295379gn7tqyv61jx80000gn/T//cc9BgV0B.s: Assembler
messages:
/var/folders/nr/l7qlwr295379gn7tqyv61jx80000gn/T//cc9BgV0B.s:29: Error: bad
alignment -- `vld1.32 {d16},[r3:128]!'
/var/folders/nr/l7qlwr295379gn7tqyv61jx80000gn/T//cc9BgV0B.s:32: Error: bad
alignment -- `vld1.32 {d7},[r2:128]'
The assembly code generated is:
algNEON:
@ args = 0, pretend = 0, frame = 0
@ frame_needed = 0, uses_anonymous_args = 0
@ link register save eliminated.
ldr r3, .L2
.LPIC0:
add r3, pc, r3
ldr r2, .L2+4
ldr r2, [r3, r2]
mov r3, r2
vld1.32 {d16}, [r3:128]! <= Offending load
vld1.32 {d6}, [r3:64]
add r2, r2, #16
vld1.32 {d7}, [r2:128] <= Offending load
vadd.f32 d16, d0, d16
vmov.f32 d0, #0.0 @ v2sf
vmla.f32 d0, d16, d6[0]
vmls.f32 d0, d16, d6[1]
vmla.f32 d0, d16, d7[0]
vmls.f32 d0, d16, d7[1]
bx lr
This does not happen at -O0.
This also happens with gcc 4.7.1.
arm-linux-androideabi-gcc -v
Using built-in specs.
COLLECT_GCC=/Users/batut/android-ndk-r8b/toolchains/arm-linux-androideabi-4.8.0/prebuilt/darwin-x86/bin/arm-linux-androideabi-gcc
COLLECT_LTO_WRAPPER=/Users/batut/android-ndk-r8b/toolchains/arm-linux-androideabi-4.8.0/prebuilt/darwin-x86/bin/../libexec/gcc/arm-linux-androideabi/4.8.0/lto-wrapper
Target: arm-linux-androideabi
Configured with:
/Users/batut/android-ndk-r8b/src/build/../gcc/gcc-4.8.0/configure
--prefix=/tmp/ndk-batut/build/toolchain/prefix --target=arm-linux-androideabi
--host=x86_64-apple-darwin --build=x86_64-apple-darwin --with-gnu-as
--with-gnu-ld --enable-languages=c,c++
--with-gmp=/tmp/ndk-batut/build/toolchain/temp-install
--with-mpfr=/tmp/ndk-batut/build/toolchain/temp-install
--with-mpc=/tmp/ndk-batut/build/toolchain/temp-install --without-ppl
--without-cloog --disable-libssp --enable-threads --disable-nls
--disable-libmudflap --disable-libgomp --disable-libstdc__-v3
--disable-sjlj-exceptions --disable-shared --disable-tls --disable-libitm
--with-float=soft --with-fpu=vfp --with-arch=armv5te --enable-target-optspace
--enable-initfini-array --disable-nls
--prefix=/tmp/ndk-batut/build/toolchain/prefix
--with-sysroot=/tmp/ndk-batut/build/toolchain/prefix/sysroot
--with-binutils-version=2.22 --with-mpfr-version=2.4.1 --with-mpc-version=0.8.1
--with-gmp-version=5.0.5 --with-gcc-version=4.8.0 --with-gdb-version=7.3.x
--disable-bootstrap --disable-libquadmath --disable-plugin --with-arch=armv5te
--program-transform-name='s&^&arm-linux-androideabi-&'
Thread model: posix
gcc version 4.8.0 20120814 (experimental) (GCC)
