[Bug target/52187] armeb-unknown-eabi not recognized as big-endian
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52187 Seth LaForge sethml at google dot com changed: What|Removed |Added CC||sethml at google dot com --- Comment #5 from Seth LaForge sethml at google dot com 2013-02-15 18:34:41 UTC --- Patch submitted: http://gcc.gnu.org/ml/gcc-patches/2013-02/msg00785.html
[Bug target/56351] New: ARM Big-Endian: storing local double to packed variable causes corruption
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56351 Bug #: 56351 Summary: ARM Big-Endian: storing local double to packed variable causes corruption Classification: Unclassified Product: gcc Version: 4.7.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target AssignedTo: unassig...@gcc.gnu.org ReportedBy: set...@google.com Created attachment 29478 -- http://gcc.gnu.org/bugzilla/attachment.cgi?id=29478 Test case which demonstrates incorrect codegen The attached code behaves incorrectly on my platform with gcc 4.7.2. In particular, the output is: val is: 1.234567 (0x3FF3C0C9:539B8887) Calling PrintAndStoreUnaligned: 57432423068808260924249171392224224725059031612325630140261797720764832869069412330679690067968.00 (0x539B8887:3FF3C0C9) unaligned_double.val is: 57432423068808260924249171392224224725059031612325630140261797720764832869069412330679690067968.00 (0x539B8887:3FF3C0C9) It appears that storing a double parameter into an unaligned variable can cause all accesses to that parameter within the function to have the upper and lower 32 bits swapped. This code is being built for a TI TMS570-series processor, although I suspect the problem would occur with any big-endian ARM target with VFPv3 floating-point support. Here's compiler info. To build the compiler with these flags requires a minor patch: http://gcc.gnu.org/ml/gcc-patches/2013-02/msg00791.html % third_party/car/embedded/toolchains/gcc_tms570/bin/armeb-unknown-eabi-gcc -v -save-temps -O1 -c gcc_bug.c -o gcc_bug.o -Wa,-adhlsn=gcc_bug.lst Using built-in specs. COLLECT_GCC=third_party/car/embedded/toolchains/gcc_tms570/bin/armeb-unknown-eabi-gcc Target: armeb-unknown-eabi Configured with: ../gcc-4.7.2/configure --prefix=/usr/local/google/armeb/toolchain --build=x86_64-cross-linux-gnu --target=armeb-unknown-eabi --host=x86_64-cross-linux-gnu --with-sysroot=/usr/local/google/armeb/sysroot --with-newlib --with-headers=../newlib-1.19.0/newlib/libc/include --disable-nls --enable-languages=c,c++ --enable-c99 --enable-long-long --with-mpfr=/usr/local/google/armeb/toolchain --with-gmp=/usr/local/google/armeb/toolchain --with-mpc=/usr/local/google/armeb/toolchain --disable-multilib --with-abi=aapcs --with-arch=armv7-r --with-mode=thumb --with-float=hard --with-fpu=vfpv3-d16 --disable-threads --disable-shared --disable-libgomp --disable-libmudflap --disable-libssp Thread model: single gcc version 4.7.2 (GCC) COLLECT_GCC_OPTIONS='-v' '-save-temps' '-O1' '-c' '-o' 'gcc_bug.o' '-march=armv7-r' '-mfloat-abi=hard' '-mfpu=vfpv3-d16' '-mabi=aapcs' '-mthumb' /google/src/cloud/sethml/head2/google3/third_party/car/embedded/toolchains/gcc_tms570/bin/../libexec/gcc/armeb-unknown-eabi/4.7.2/cc1 -E -quiet -v -iprefix /google/src/cloud/sethml/head2/google3/third_party/car/embedded/toolchains/gcc_tms570/bin/../lib/gcc/armeb-unknown-eabi/4.7.2/ -D__USES_INITFINI__ gcc_bug.c -march=armv7-r -mfloat-abi=hard -mfpu=vfpv3-d16 -mabi=aapcs -mthumb -O1 -fpch-preprocess -o gcc_bug.i ignoring duplicate directory /google/src/cloud/sethml/head2/google3/third_party/car/embedded/toolchains/gcc_tms570/bin/../lib/gcc/../../lib/gcc/armeb-unknown-eabi/4.7.2/include ignoring nonexistent directory /usr/local/google/armeb/sysroot/usr/local/include ignoring duplicate directory /google/src/cloud/sethml/head2/google3/third_party/car/embedded/toolchains/gcc_tms570/bin/../lib/gcc/../../lib/gcc/armeb-unknown-eabi/4.7.2/include-fixed ignoring duplicate directory /google/src/cloud/sethml/head2/google3/third_party/car/embedded/toolchains/gcc_tms570/bin/../lib/gcc/../../lib/gcc/armeb-unknown-eabi/4.7.2/../../../../armeb-unknown-eabi/include #include ... search starts here: #include ... search starts here: /google/src/cloud/sethml/head2/google3/third_party/car/embedded/toolchains/gcc_tms570/bin/../lib/gcc/armeb-unknown-eabi/4.7.2/include /google/src/cloud/sethml/head2/google3/third_party/car/embedded/toolchains/gcc_tms570/bin/../lib/gcc/armeb-unknown-eabi/4.7.2/include-fixed /google/src/cloud/sethml/head2/google3/third_party/car/embedded/toolchains/gcc_tms570/bin/../lib/gcc/armeb-unknown-eabi/4.7.2/../../../../armeb-unknown-eabi/include /usr/local/google/armeb/sysroot/usr/include End of search list. COLLECT_GCC_OPTIONS='-v' '-save-temps' '-O1' '-c' '-o' 'gcc_bug.o' '-march=armv7-r' '-mfloat-abi=hard' '-mfpu=vfpv3-d16' '-mabi=aapcs' '-mthumb' /google/src/cloud/sethml/head2/google3/third_party/car/embedded/toolchains/gcc_tms570/bin/../libexec/gcc/armeb-unknown-eabi/4.7.2/cc1 -fpreprocessed gcc_bug.i -quiet -dumpbase gcc_bug.c -march=armv7-r -mfloat-abi=hard -mfpu=vfpv3-d16 -mabi=aapcs -mthumb -auxbase-strip gcc_bug.o -O1 -version -o gcc_bug.s GNU C (GCC) version 4.7.2 (armeb-unknown-eabi) compiled by GNU C version 4.6.x-google 20120601 (prerelease), GMP version 5.0.5, MPFR version 3.1.1, MPC version 1.0.1 GGC heuristics: --param
[Bug target/56351] ARM Big-Endian: storing local double to packed variable causes corruption
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56351
--- Comment #1 from Seth LaForge sethml at google dot com 2013-02-15 20:16:43
UTC ---
Ugh, my attachment was a bit mangled. Here's the source to stimulate the issue
- gcc_bug.c:
#include stdio.h
void PrintDouble(double v) __attribute__((noinline));
void PrintDouble(double v) {
union { double d; int i[2]; } u = { v };
printf(%f (0x%08X:%08X), v, u.i[0], u.i[1]);
}
struct { double val; } __attribute__((packed)) unaligned_double;
void PrintAndStoreUnaligned(double v) __attribute__((noinline));
void PrintAndStoreUnaligned(double v) {
PrintDouble(v);
unaligned_double.val = v;
}
int main() {
double val = 1.234567;
printf(val is: );
PrintDouble(val);
printf(\nCalling PrintAndStoreUnaligned: );
PrintAndStoreUnaligned(val);
printf(\nunaligned_double.val is: );
PrintDouble(unaligned_double.val);
printf(\n);
return 0;
}
[Bug target/56351] ARM Big-Endian: storing local double to packed variable causes corruption
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56351
Seth LaForge sethml at google dot com changed:
What|Removed |Added
CC||sethml at google dot com
--- Comment #3 from Seth LaForge sethml at google dot com 2013-02-15 22:43:56
UTC ---
Thank you Andrew, super useful pointer! Yes, that patch does appear to fix my
problem. I've backported it to gcc 4.7 and posted a patch:
http://gcc.gnu.org/ml/gcc-patches/2013-02/msg00800.html
With gcc 4.7.2 with my/Julian's patch, I get correct code:
43PrintAndStoreUnaligned:
46 0020 B538push {r3, r4, r5, lr}
47 0022 EC523B10fmrrd r3, r2, d0
48 0026 4614mov r4, r2
49 0028 461Dmov r5, r3
50 002a 4622mov r2, r4
51 002c EC423B10fmdrr d0, r3, r2
52 0030 F7FEbl PrintDouble
53 0034 F2400300movw r3, #:lower16:unaligned_double
54 0038 F2C00300movt r3, #:upper16:unaligned_double
55 003c 605Dstr r5, [r3, #4]
56 003e 601Cstr r4, [r3, #0]
57 0040 BD38pop {r3, r4, r5, pc}
[Bug c++/20589] error: 'anonymous enum' is/uses anonymous type'
--- Additional Comments From sethml at google dot com 2005-08-05 03:43 --- The C++ working group examined this issue in April as core language issue 488: http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#488 They tentatively concluded that type deduction should fail in this case, leaving the built-in operator==(int,int) version as the only viable candidate and thus the code attached to this bug report would compile. It seems likely that this decision will hold, that the standard will be clarified, making this code valid. Can we get this bug re-opened, and perhaps change GCC 4 to accept this code in anticipation of the C++ standard changing to explicitly allow it? -- What|Removed |Added CC||sethml at google dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20589
