[PATCH 1/1] LoongArch: Fix ptr mangling/demangling features.
Adhemerval Zanella Netto
adhemerval.zanella@linaro.org
Mon Aug 29 12:41:29 GMT 2022
On 29/08/22 04:08, Xi Ruoyao wrote:
> I'm OK with either this or the simplified version w/o ac check.
>
> Not sure about Glibc policy about committing a change (does a port
> maintainer needs approval to commit a change within this port?)
Afaik as long the arch-maintainer is ok with the change and there is
no blocker it should be ok to push. I stil prefer to just use la.pcrel,
since it way simpler and I am really sceptical that using pcalau12i will
yield any real performance difference, but it is not a blocker from my
part.
>
> On Fri, 2022-08-26 at 16:03 +0800, caiyinyu wrote:
>> Co-authored-by: Xi Ruoyao <xry111@xry111.site>
>> ---
>> config.h.in | 3 ++
>> sysdeps/loongarch/__longjmp.S | 2 +-
>> sysdeps/loongarch/configure | 26 ++++++++++++++
>> sysdeps/loongarch/configure.ac | 14 ++++++++
>> sysdeps/loongarch/setjmp.S | 2 +-
>> sysdeps/unix/sysv/linux/loongarch/sysdep.h | 40 +++++++++++++--------
>> -
>> 6 files changed, 68 insertions(+), 19 deletions(-)
>>
>> diff --git a/config.h.in b/config.h.in
>> index 43d32518ab..b182de0e91 100644
>> --- a/config.h.in
>> +++ b/config.h.in
>> @@ -138,6 +138,9 @@
>> /* LOONGARCH floating-point ABI for ld.so. */
>> #undef LOONGARCH_ABI_FRLEN
>>
>> +/* To Indicate whether we can use explicit relocs or not. */
>> +#undef HAVE_LOONGARCH_EXPLICIT_RELOCS
>> +
>> /* Linux specific: minimum supported kernel version. */
>> #undef __LINUX_KERNEL_VERSION
>>
>> diff --git a/sysdeps/loongarch/__longjmp.S
>> b/sysdeps/loongarch/__longjmp.S
>> index c2c5b56a80..4207376f5e 100644
>> --- a/sysdeps/loongarch/__longjmp.S
>> +++ b/sysdeps/loongarch/__longjmp.S
>> @@ -22,7 +22,7 @@
>> ENTRY (__longjmp)
>> #ifdef PTR_MANGLE
>> REG_L t0, a0, 0*SZREG
>> - PTR_DEMANGLE (ra, t0, t1, t2)
>> + PTR_DEMANGLE (ra, t0, t1)
>> REG_L t0, a0, 1*SZREG
>> PTR_DEMANGLE2 (sp, t0, t1)
>> #else
>> diff --git a/sysdeps/loongarch/configure b/sysdeps/loongarch/configure
>> index 43b54d4965..54385786d2 100644
>> --- a/sysdeps/loongarch/configure
>> +++ b/sysdeps/loongarch/configure
>> @@ -3,3 +3,29 @@
>>
>> $as_echo "#define HIDDEN_VAR_NEEDS_DYNAMIC_RELOC 1" >>confdefs.h
>>
>> +
>> +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether explicit
>> relocs can be used" >&5
>> +$as_echo_n "checking whether explicit relocs can be used... " >&6; }
>> +if ${libc_cv_loongarch_explicit_relocs+:} false; then :
>> + $as_echo_n "(cached) " >&6
>> +else
>> + cat > conftest.s << EOF
>> +x: pcalau12i \$t0, %pc_hi20(x)
>> +EOF
>> +libc_cv_loongarch_explicit_relocs=no
>> +if { ac_try='${CC-cc} -c $CFLAGS conftest.s -o conftest.o 1>&5'
>> + { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; }
>>> &5
>> + (eval $ac_try) 2>&5
>> + ac_status=$?
>> + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
>> + test $ac_status = 0; }; }; then
>> + libc_cv_loongarch_explicit_relocs=yes
>> +fi
>> +rm -f conftest*
>> +fi
>> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result:
>> $libc_cv_loongarch_explicit_relocs" >&5
>> +$as_echo "$libc_cv_loongarch_explicit_relocs" >&6; }
>> +if test $libc_cv_loongarch_explicit_relocs = yes; then
>> + $as_echo "#define HAVE_LOONGARCH_EXPLICIT_RELOCS 1" >>confdefs.h
>> +
>> +fi
>> diff --git a/sysdeps/loongarch/configure.ac
>> b/sysdeps/loongarch/configure.ac
>> index f744367bf3..c5d3cb5ead 100644
>> --- a/sysdeps/loongarch/configure.ac
>> +++ b/sysdeps/loongarch/configure.ac
>> @@ -4,3 +4,17 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level
>> source directory.
>> dnl It is always possible to access static and hidden symbols in an
>> dnl position independent way.
>> AC_DEFINE(HIDDEN_VAR_NEEDS_DYNAMIC_RELOC)
>> +
>> +AC_CACHE_CHECK(whether explicit relocs can be used,
>> + libc_cv_loongarch_explicit_relocs, [dnl
>> +cat > conftest.s << EOF
>> +x: pcalau12i \$t0, %pc_hi20(x)
>> +EOF
>> +libc_cv_loongarch_explicit_relocs=no
>> +if AC_TRY_COMMAND(${CC-cc} -c $CFLAGS conftest.s -o conftest.o
>> 1>&AS_MESSAGE_LOG_FD); then
>> + libc_cv_loongarch_explicit_relocs=yes
>> +fi
>> +rm -f conftest*])
>> +if test $libc_cv_loongarch_explicit_relocs = yes; then
>> + AC_DEFINE(HAVE_LOONGARCH_EXPLICIT_RELOCS)
>> +fi
>> diff --git a/sysdeps/loongarch/setjmp.S b/sysdeps/loongarch/setjmp.S
>> index ec4ddc72da..298bb02a82 100644
>> --- a/sysdeps/loongarch/setjmp.S
>> +++ b/sysdeps/loongarch/setjmp.S
>> @@ -30,7 +30,7 @@ END (setjmp)
>>
>> ENTRY (__sigsetjmp)
>> #ifdef PTR_MANGLE
>> - PTR_MANGLE (t0, ra, t1, t2)
>> + PTR_MANGLE (t0, ra, t1)
>> REG_S t0, a0, 0*SZREG
>> PTR_MANGLE2 (t0, sp, t1)
>> REG_S t0, a0, 1*SZREG
>> diff --git a/sysdeps/unix/sysv/linux/loongarch/sysdep.h
>> b/sysdeps/unix/sysv/linux/loongarch/sysdep.h
>> index 157cbd6c6b..0a8773c38d 100644
>> --- a/sysdeps/unix/sysv/linux/loongarch/sysdep.h
>> +++ b/sysdeps/unix/sysv/linux/loongarch/sysdep.h
>> @@ -316,29 +316,35 @@ extern long int __syscall_error (long int
>> neg_errno);
>>
>> /* Pointer mangling is supported for LoongArch. */
>>
>> -/* Load or store to/from a got-relative EXPR into/from G, using T.
>> +/* Load a got-relative EXPR into G, using T.
>> Note G and T are register names. */
>> -#define LDST_GLOBAL(OP, G, T, EXPR) \
>> - pcalau12i T, %got_pc_hi20(EXPR); \
>> - OP T, T, %got_pc_lo12(EXPR); \
>> - OP G, T, 0;
>> +#define LD_GLOBAL(G, EXPR) \
>> + la.global G, EXPR; \
>> + REG_L G, G, 0;
>>
>> -/* Load or store to/from a pc-relative EXPR into/from G, using T.
>> +/* Load a pc-relative EXPR into G, using T.
>> Note G and T are register names. */
>> -#define LDST_PCREL(OP, G, T, EXPR) \
>> - pcalau12i T, %pc_hi20(EXPR); \
>> - OP G, T, %pc_lo12(EXPR);
>> +
>> +#ifdef HAVE_LOONGARCH_EXPLICIT_RELOCS
>> +#define LD_PCREL(G, EXPR) \
>> + pcalau12i G, %pc_hi20(EXPR); \
>> + REG_L G, G, %pc_lo12(EXPR);
>> +#else
>> +#define LD_PCREL(G, EXPR) \
>> + la.pcrel G, EXPR; \
>> + REG_L G, G, 0;
>> +#endif
>>
>> #if (IS_IN (rtld) \
>> || (!defined SHARED && (IS_IN (libc) \
>> || IS_IN (libpthread))))
>>
>> #ifdef __ASSEMBLER__
>> -#define PTR_MANGLE(dst, src, guard, tmp) \
>> - LDST_PCREL (REG_L, guard, tmp, __pointer_chk_guard_local); \
>> +#define PTR_MANGLE(dst, src, guard) \
>> + LD_PCREL (guard, __pointer_chk_guard_local); \
>> PTR_MANGLE2 (dst, src, guard);
>> -#define PTR_DEMANGLE(dst, src, guard, tmp) \
>> - LDST_PCREL (REG_L, guard, tmp, __pointer_chk_guard_local); \
>> +#define PTR_DEMANGLE(dst, src, guard) \
>> + LD_PCREL (guard, __pointer_chk_guard_local); \
>> PTR_DEMANGLE2 (dst, src, guard);
>> /* Use PTR_MANGLE2 for efficiency if guard is already loaded. */
>> #define PTR_MANGLE2(dst, src, guard) \
>> @@ -355,11 +361,11 @@ extern uintptr_t __pointer_chk_guard_local
>> attribute_relro attribute_hidden;
>> #else
>>
>> #ifdef __ASSEMBLER__
>> -#define PTR_MANGLE(dst, src, guard, tmp) \
>> - LDST_GLOBAL (REG_L, guard, tmp, __pointer_chk_guard); \
>> +#define PTR_MANGLE(dst, src, guard) \
>> + LD_GLOBAL (guard, __pointer_chk_guard); \
>> PTR_MANGLE2 (dst, src, guard);
>> -#define PTR_DEMANGLE(dst, src, guard, tmp) \
>> - LDST_GLOBAL (REG_L, guard, tmp, __pointer_chk_guard); \
>> +#define PTR_DEMANGLE(dst, src, guard) \
>> + LD_GLOBAL (guard, __pointer_chk_guard); \
>> PTR_DEMANGLE2 (dst, src, guard);
>> /* Use PTR_MANGLE2 for efficiency if guard is already loaded. */
>> #define PTR_MANGLE2(dst, src, guard) \
>
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