[PATCH 1/2] LoongArch: Fix ptr mangling/demangling features.

[caiyinyu]

Co-authored-by: Xi Ruoyao <xry111@xry111.site>
---
 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 +++++++++++++---------
 5 files changed, 65 insertions(+), 19 deletions(-)

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) \
-- 
2.31.1