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| author | Nathan Chancellor <natechancellor@gmail.com> | 2020-04-21 14:47:04 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-06-22 09:31:00 +0200 |
| commit | 338ff29604d957aeefb16a5df52d3bbb7a1e025a (patch) | |
| tree | 63991f04d08ed0d9e0da3ea1a646b90342b725f0 | |
| parent | 4fbc334749e77bc3b67555e7307d821372a09dc4 (diff) | |
| download | linux-stable-338ff29604d957aeefb16a5df52d3bbb7a1e025a.tar.gz linux-stable-338ff29604d957aeefb16a5df52d3bbb7a1e025a.tar.bz2 linux-stable-338ff29604d957aeefb16a5df52d3bbb7a1e025a.zip | |
lib/mpi: Fix 64-bit MIPS build with Clang
[ Upstream commit 18f1ca46858eac22437819937ae44aa9a8f9f2fa ]
When building 64r6_defconfig with CONFIG_MIPS32_O32 disabled and
CONFIG_CRYPTO_RSA enabled:
lib/mpi/generic_mpih-mul1.c:37:24: error: invalid use of a cast in a
inline asm context requiring an l-value: remove the cast
or build with -fheinous-gnu-extensions
umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/mpi/longlong.h:664:22: note: expanded from macro 'umul_ppmm'
: "=d" ((UDItype)(w0))
~~~~~~~~~~^~~
lib/mpi/generic_mpih-mul1.c:37:13: error: invalid use of a cast in a
inline asm context requiring an l-value: remove the cast
or build with -fheinous-gnu-extensions
umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/mpi/longlong.h:668:22: note: expanded from macro 'umul_ppmm'
: "=d" ((UDItype)(w1))
~~~~~~~~~~^~~
2 errors generated.
This special case for umul_ppmm for MIPS64r6 was added in
commit bbc25bee37d2b ("lib/mpi: Fix umul_ppmm() for MIPS64r6"), due to
GCC being inefficient and emitting a __multi3 intrinsic.
There is no such issue with clang; with this patch applied, I can build
this configuration without any problems and there are no link errors
like mentioned in the commit above (which I can still reproduce with
GCC 9.3.0 when that commit is reverted). Only use this definition when
GCC is being used.
This really should have been caught by commit b0c091ae04f67 ("lib/mpi:
Eliminate unused umul_ppmm definitions for MIPS") when I was messing
around in this area but I was not testing 64-bit MIPS at the time.
Link: https://github.com/ClangBuiltLinux/linux/issues/885
Reported-by: Dmitry Golovin <dima@golovin.in>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | lib/mpi/longlong.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/mpi/longlong.h b/lib/mpi/longlong.h index 891e1c3549c4..afbd99987cf8 100644 --- a/lib/mpi/longlong.h +++ b/lib/mpi/longlong.h @@ -653,7 +653,7 @@ do { \ ************** MIPS/64 ************** ***************************************/ #if (defined(__mips) && __mips >= 3) && W_TYPE_SIZE == 64 -#if defined(__mips_isa_rev) && __mips_isa_rev >= 6 +#if defined(__mips_isa_rev) && __mips_isa_rev >= 6 && defined(CONFIG_CC_IS_GCC) /* * GCC ends up emitting a __multi3 intrinsic call for MIPS64r6 with the plain C * code below, so we special case MIPS64r6 until the compiler can do better. |