binutils/LoongArch-Add-support-for-the-third-expression-of-.a.patch

From 3df3fec5862a2d6adec7dc469e7c53596e0ca464 Mon Sep 17 00:00:00 2001
From: mengqinggang <mengqinggang@loongson.cn>
Date: Fri, 8 Dec 2023 15:15:50 +0800
Subject: [PATCH 023/123] LoongArch: Add support for the third expression of
 .align for R_LARCH_ALIGN

If the symbol index is not zero, the addend is used to represent
the first and the third expressions of the .align.

The lowest 8 bits are used to represent the first expression.
Other bits are used to represent the third expression.

The addend of R_LARCH_ALIGN for ".align 5, ,4" is 0x405.
The addend of R_LARCH_ALIGN for ".balign 32, ,4" is 0x405.
---
 bfd/elfnn-loongarch.c                         | 71 ++++++++++++-------
 bfd/elfxx-loongarch.c                         | 10 ++-
 gas/config/tc-loongarch.c                     | 20 ++++--
 gas/config/tc-loongarch.h                     |  4 +-
 gas/testsuite/gas/loongarch/relax_align.d     | 46 +++++++-----
 gas/testsuite/gas/loongarch/relax_align.s     |  4 +-
 ld/testsuite/ld-elf/anno-sym.d                |  2 +
 ld/testsuite/ld-loongarch-elf/anno-sym.d      |  7 ++
 ld/testsuite/ld-loongarch-elf/anno-sym.l      |  4 ++
 ld/testsuite/ld-loongarch-elf/anno-sym.s      | 13 ++++
 .../ld-loongarch-elf/ld-loongarch-elf.exp     |  1 +
 ld/testsuite/ld-loongarch-elf/relax-align.dd  |  5 +-
 ld/testsuite/ld-loongarch-elf/relax-align.s   |  5 +-
 ld/testsuite/ld-loongarch-elf/relax.exp       |  2 +-
 14 files changed, 134 insertions(+), 60 deletions(-)
 create mode 100644 ld/testsuite/ld-loongarch-elf/anno-sym.d
 create mode 100644 ld/testsuite/ld-loongarch-elf/anno-sym.l
 create mode 100644 ld/testsuite/ld-loongarch-elf/anno-sym.s

diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
index 6fd6a04d..8e61d8d2 100644
--- a/bfd/elfnn-loongarch.c
+++ b/bfd/elfnn-loongarch.c
@@ -3851,44 +3851,53 @@ loongarch_relax_align (bfd *abfd, asection *sec,
 			Elf_Internal_Rela *rel,
 			bfd_vma symval)
 {
-  bfd_byte *contents = elf_section_data (sec)->this_hdr.contents;
-  bfd_vma alignment = 1, pos;
-  while (alignment <= rel->r_addend)
-    alignment *= 2;
+  bfd_vma  addend, max = 0, alignment = 1;
 
-  symval -= rel->r_addend;
-  bfd_vma aligned_addr = ((symval - 1) & ~(alignment - 1)) + alignment;
-  bfd_vma nop_bytes = aligned_addr - symval;
+  int index = ELFNN_R_SYM (rel->r_info);
+  if (index > 0)
+    {
+      alignment = 1 << (rel->r_addend & 0xff);
+      max = rel->r_addend >> 8;
+    }
+  else
+    alignment = rel->r_addend + 4;
 
-  /* Once we've handled an R_LARCH_ALIGN, we can't relax anything else.  */
-  sec->sec_flg0 = true;
+  addend = alignment - 4; /* The bytes of NOPs added by R_LARCH_ALIGN.  */
+  symval -= addend; /* The address of first NOP added by R_LARCH_ALIGN.  */
+  bfd_vma aligned_addr = ((symval - 1) & ~(alignment - 1)) + alignment;
+  bfd_vma need_nop_bytes = aligned_addr - symval; /* */
 
   /* Make sure there are enough NOPs to actually achieve the alignment.  */
-  if (rel->r_addend < nop_bytes)
+  if (addend < need_nop_bytes)
     {
       _bfd_error_handler
 	(_("%pB(%pA+%#" PRIx64 "): %" PRId64 " bytes required for alignment "
 	   "to %" PRId64 "-byte boundary, but only %" PRId64 " present"),
 	 abfd, sym_sec, (uint64_t) rel->r_offset,
-	 (int64_t) nop_bytes, (int64_t) alignment, (int64_t) rel->r_addend);
+	 (int64_t) need_nop_bytes, (int64_t) alignment, (int64_t) addend);
       bfd_set_error (bfd_error_bad_value);
       return false;
     }
 
-  /* Delete the reloc.  */
+  /* Once we've handled an R_LARCH_ALIGN in a section,
+     we can't relax anything else in this section.  */
+  sec->sec_flg0 = true;
   rel->r_info = ELFNN_R_INFO (0, R_LARCH_NONE);
 
+  /* If skipping more bytes than the specified maximum,
+     then the alignment is not done at all and delete all NOPs.  */
+  if (max > 0 && need_nop_bytes > max)
+    return loongarch_relax_delete_bytes (abfd, sec, rel->r_offset,
+					  addend, link_info);
+
   /* If the number of NOPs is already correct, there's nothing to do.  */
-  if (nop_bytes == rel->r_addend)
+  if (need_nop_bytes == addend)
     return true;
 
-  /* Write as many LOONGARCH NOPs as we need.  */
-  for (pos = 0; pos < (nop_bytes & -4); pos += 4)
-    bfd_putl32 (LARCH_NOP, contents + rel->r_offset + pos);
-
   /* Delete the excess NOPs.  */
-  return loongarch_relax_delete_bytes (abfd, sec, rel->r_offset + nop_bytes,
-				   rel->r_addend - nop_bytes, link_info);
+  return loongarch_relax_delete_bytes (abfd, sec,
+					rel->r_offset + need_nop_bytes,
+					addend - need_nop_bytes, link_info);
 }
 
 static bool
@@ -3897,8 +3906,8 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
 			       bool *again)
 {
   struct loongarch_elf_link_hash_table *htab = loongarch_elf_hash_table (info);
-  Elf_Internal_Shdr *symtab_hdr = &elf_symtab_hdr (abfd);
   struct bfd_elf_section_data *data = elf_section_data (sec);
+  Elf_Internal_Shdr *symtab_hdr = &elf_symtab_hdr (abfd);
   Elf_Internal_Rela *relocs;
   *again = false;
 
@@ -3931,7 +3940,7 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
 						   0, NULL, NULL, NULL)))
     return true;
 
-      data->relocs = relocs;
+  data->relocs = relocs;
 
   for (unsigned int i = 0; i < sec->reloc_count; i++)
     {
@@ -3939,6 +3948,7 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
       asection *sym_sec;
       bfd_vma symval;
       unsigned long r_symndx = ELFNN_R_SYM (rel->r_info);
+      unsigned long r_type = ELFNN_R_TYPE (rel->r_info);
       bool local_got = false;
       char symtype;
       struct elf_link_hash_entry *h = NULL;
@@ -3950,7 +3960,7 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
 	  if (ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC)
 	    continue;
 
-	  if (sym->st_shndx == SHN_UNDEF)
+	  if (sym->st_shndx == SHN_UNDEF || R_LARCH_ALIGN == r_type)
 	    {
 	      sym_sec = sec;
 	      symval = rel->r_offset;
@@ -3976,9 +3986,9 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
 	    continue;
 
 	  if ((h->root.type == bfd_link_hash_defined
-		    || h->root.type == bfd_link_hash_defweak)
-		   && h->root.u.def.section != NULL
-		   && h->root.u.def.section->output_section != NULL)
+		  || h->root.type == bfd_link_hash_defweak)
+		&& h->root.u.def.section != NULL
+		&& h->root.u.def.section->output_section != NULL)
 	    {
 	      symval = h->root.u.def.value;
 	      sym_sec = h->root.u.def.section;
@@ -4004,12 +4014,21 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
 	   if (symtype != STT_SECTION)
 	     symval += rel->r_addend;
 	}
+      /* For R_LARCH_ALIGN, symval is sec_addr (sym_sec) + rel->r_offset
+	 + (alingmeng - 4).
+	 If r_symndx is 0, alignmeng-4 is r_addend.
+	 If r_symndx > 0, alignment-4 is 2^(r_addend & 0xff)-4.  */
+      else if (R_LARCH_ALIGN == r_type)
+	if (r_symndx > 0)
+	  symval += ((1 << (rel->r_addend & 0xff)) - 4);
+	else
+	  symval += rel->r_addend;
       else
 	symval += rel->r_addend;
 
       symval += sec_addr (sym_sec);
 
-      switch (ELFNN_R_TYPE (rel->r_info))
+      switch (r_type)
 	{
 	case R_LARCH_ALIGN:
 	  if (1 == info->relax_pass)
diff --git a/bfd/elfxx-loongarch.c b/bfd/elfxx-loongarch.c
index d93b7904..679b79f3 100644
--- a/bfd/elfxx-loongarch.c
+++ b/bfd/elfxx-loongarch.c
@@ -1395,9 +1395,13 @@ static loongarch_reloc_howto_type loongarch_howto_table[] =
 	 NULL,					/* adjust_reloc_bits.  */
 	 NULL),					/* larch_reloc_type_name.  */
 
-  /* Indicates an alignment statement.  The addend field encodes how many
-     bytes of NOPs follow the statement.  The desired alignment is the
-     addend rounded up to the next power of two.  */
+  /* Indicates an alignment statement. f the symbol index is 0,
+     the addend indicates the number of bytes occupied by nop instructions
+     at the relocation offset. The alignment boundary is specified by the
+     addend rounded up to the next power of two.
+     If the symbol index is not 0, the addend indicates the first and third
+     expressions of .align. The lowest 8 bits are used to represent the first
+     expression, other bits are used to represent the third expression.  */
   LOONGARCH_HOWTO (R_LARCH_ALIGN,		/* type (102).  */
 	 0,					/* rightshift.  */
 	 0,					/* size.  */
diff --git a/gas/config/tc-loongarch.c b/gas/config/tc-loongarch.c
index 367a0b6c..9b912daf 100644
--- a/gas/config/tc-loongarch.c
+++ b/gas/config/tc-loongarch.c
@@ -1652,14 +1652,16 @@ loongarch_make_nops (char *buf, bfd_vma bytes)
    the correct alignment now because of other linker relaxations.  */
 
 bool
-loongarch_frag_align_code (int n)
+loongarch_frag_align_code (int n, int max)
 {
-  bfd_vma bytes = (bfd_vma) 1 << n;
-  bfd_vma insn_alignment = 4;
-  bfd_vma worst_case_bytes = bytes - insn_alignment;
   char *nops;
+  symbolS *s;
   expressionS ex;
 
+  bfd_vma insn_alignment = 4;
+  bfd_vma bytes = (bfd_vma) 1 << n;
+  bfd_vma worst_case_bytes = bytes - insn_alignment;
+
   /* If we are moving to a smaller alignment than the instruction size, then no
      alignment is required.  */
   if (bytes <= insn_alignment)
@@ -1671,8 +1673,14 @@ loongarch_frag_align_code (int n)
 
   nops = frag_more (worst_case_bytes);
 
-  ex.X_op = O_constant;
-  ex.X_add_number = worst_case_bytes;
+  s = symbol_find (".Lla-relax-align");
+  if (s == NULL)
+    s = (symbolS *)local_symbol_make (".Lla-relax-align", now_seg,
+				      &zero_address_frag, 0);
+
+  ex.X_add_symbol = s;
+  ex.X_op = O_symbol;
+  ex.X_add_number = (max << 8) | n;
 
   loongarch_make_nops (nops, worst_case_bytes);
 
diff --git a/gas/config/tc-loongarch.h b/gas/config/tc-loongarch.h
index 4afa3842..194ee107 100644
--- a/gas/config/tc-loongarch.h
+++ b/gas/config/tc-loongarch.h
@@ -49,11 +49,11 @@ extern int loongarch_relax_frag (asection *, struct frag *, long);
 #define md_undefined_symbol(name) (0)
 #define md_operand(x)
 
-extern bool loongarch_frag_align_code (int);
+extern bool loongarch_frag_align_code (int, int);
 #define md_do_align(N, FILL, LEN, MAX, LABEL)				\
   if ((N) != 0 && !(FILL) && !need_pass_2 && subseg_text_p (now_seg))	\
     {									\
-      if (loongarch_frag_align_code (N))				\
+      if (loongarch_frag_align_code (N, MAX))				\
 	goto LABEL;							\
     }
 
diff --git a/gas/testsuite/gas/loongarch/relax_align.d b/gas/testsuite/gas/loongarch/relax_align.d
index 1810eb4c..2cc6c86d 100644
--- a/gas/testsuite/gas/loongarch/relax_align.d
+++ b/gas/testsuite/gas/loongarch/relax_align.d
@@ -1,4 +1,4 @@
-#as:
+#as: --no-warn
 #objdump: -dr
 #skip: loongarch32-*-*
 
@@ -7,20 +7,30 @@
 
 Disassembly of section .text:
 
-00000000.* <L1>:
-[ 	]+0:[ 	]+1a000004[ 	]+pcalau12i[ 	]+\$a0,[ 	]+0
-[ 	]+0:[ 	]+R_LARCH_PCALA_HI20[ 	]+L1
-[ 	]+0:[ 	]+R_LARCH_RELAX[ 	]+\*ABS\*
-[ 	]+4:[ 	]+02c00084[ 	]+addi\.d[ 	]+\$a0,[ 	]+\$a0,[ 	]+0
-[ 	]+4:[ 	]+R_LARCH_PCALA_LO12[ 	]+L1
-[ 	]+4:[ 	]+R_LARCH_RELAX[ 	]+\*ABS\*
-[ 	]+8:[ 	]+03400000[ 	]+nop[ 	]+
-[ 	]+8:[ 	]+R_LARCH_ALIGN[ 	]+\*ABS\*\+0xc
-[ 	]+c:[ 	]+03400000[ 	]+nop[ 	]+
-[ 	]+10:[ 	]+03400000[ 	]+nop[ 	]+
-[ 	]+14:[ 	]+1a000004[ 	]+pcalau12i[ 	]+\$a0,[ 	]+0
-[ 	]+14:[ 	]+R_LARCH_PCALA_HI20[ 	]+L1
-[ 	]+14:[ 	]+R_LARCH_RELAX[ 	]+\*ABS\*
-[ 	]+18:[ 	]+02c00084[ 	]+addi\.d[ 	]+\$a0,[ 	]+\$a0,[ 	]+0
-[ 	]+18:[ 	]+R_LARCH_PCALA_LO12[ 	]+L1
-[ 	]+18:[ 	]+R_LARCH_RELAX[ 	]+\*ABS\*
+[ 	]*0000000000000000 <.Lla-relax-align>:
+[ 	]+0:[ 	]+1a000004[ 	]+pcalau12i[ 	]+\$a0, 0
+[ 	]+0: R_LARCH_PCALA_HI20[ 	]+L1
+[ 	]+0: R_LARCH_RELAX[ 	]+\*ABS\*
+[ 	]+4:[ 	]+02c00084[ 	]+addi.d[ 	]+\$a0, \$a0, 0
+[ 	]+4: R_LARCH_PCALA_LO12[ 	]+L1
+[ 	]+4: R_LARCH_RELAX[ 	]+\*ABS\*
+[ 	]+8:[ 	]+03400000[ 	]+nop.*
+[ 	]+8: R_LARCH_ALIGN[ 	]+.Lla-relax-align\+0x4
+[ 	]+c:[ 	]+03400000[ 	]+nop.*
+[ 	]+10:[ 	]+03400000[ 	]+nop.*
+[ 	]+14:[ 	]+1a000004[ 	]+pcalau12i[ 	]+\$a0, 0
+[ 	]+14: R_LARCH_PCALA_HI20[ 	]+L1
+[ 	]+14: R_LARCH_RELAX[ 	]+\*ABS\*
+[ 	]+18:[ 	]+02c00084[ 	]+addi.d[ 	]+\$a0, \$a0, 0
+[ 	]+18: R_LARCH_PCALA_LO12[ 	]+L1
+[ 	]+18: R_LARCH_RELAX[ 	]+\*ABS\*
+[ 	]+1c:[ 	]+03400000[ 	]+nop.*
+[ 	]+1c: R_LARCH_ALIGN[ 	]+.Lla-relax-align\+0x404
+[ 	]+20:[ 	]+03400000[ 	]+nop.*
+[ 	]+24:[ 	]+03400000[ 	]+nop.*
+[ 	]+28:[ 	]+1a000004[ 	]+pcalau12i[ 	]+\$a0, 0
+[ 	]+28: R_LARCH_PCALA_HI20[ 	]+L1
+[ 	]+28: R_LARCH_RELAX[ 	]+\*ABS\*
+[ 	]+2c:[ 	]+02c00084[ 	]+addi.d[ 	]+\$a0, \$a0, 0
+[ 	]+2c: R_LARCH_PCALA_LO12[ 	]+L1
+[ 	]+2c: R_LARCH_RELAX[ 	]+\*ABS\*
diff --git a/gas/testsuite/gas/loongarch/relax_align.s b/gas/testsuite/gas/loongarch/relax_align.s
index 3880d783..c0177c88 100644
--- a/gas/testsuite/gas/loongarch/relax_align.s
+++ b/gas/testsuite/gas/loongarch/relax_align.s
@@ -1,5 +1,7 @@
   .text
-L1:
+.L1:
   la.local $a0, L1
   .align 4
   la.local $a0, L1
+  .align 4, , 4
+  la.local $a0, L1
diff --git a/ld/testsuite/ld-elf/anno-sym.d b/ld/testsuite/ld-elf/anno-sym.d
index 9e53c4a9..f1ce21f9 100644
--- a/ld/testsuite/ld-elf/anno-sym.d
+++ b/ld/testsuite/ld-elf/anno-sym.d
@@ -3,3 +3,5 @@
 #error_output: anno-sym.l
 # The mips-irix6 target fails this test because it does not find any function symbols.  Not sure why.
 #skip: *-*-irix*
+# The .align generate a local symbol .Lla-relax-align.
+#skip: loongarch*-*-*
diff --git a/ld/testsuite/ld-loongarch-elf/anno-sym.d b/ld/testsuite/ld-loongarch-elf/anno-sym.d
new file mode 100644
index 00000000..a58f4a6c
--- /dev/null
+++ b/ld/testsuite/ld-loongarch-elf/anno-sym.d
@@ -0,0 +1,7 @@
+# Copied from ld-elf, add -mno-relax to prevent generate .Lla-relax-align symbol
+# Check that linking anno-sym.o produces an undefined reference message referring to '_start' and not 'annobin_hello.c'
+#as: -mno-relax
+#ld:  -e _start
+#error_output: anno-sym.l
+# The mips-irix6 target fails this test because it does not find any function symbols.  Not sure why.
+#skip: *-*-irix*
diff --git a/ld/testsuite/ld-loongarch-elf/anno-sym.l b/ld/testsuite/ld-loongarch-elf/anno-sym.l
new file mode 100644
index 00000000..ee9611ae
--- /dev/null
+++ b/ld/testsuite/ld-loongarch-elf/anno-sym.l
@@ -0,0 +1,4 @@
+#...
+.*: in function `(|_)start':
+.*: undefined reference to `foo'
+#pass
diff --git a/ld/testsuite/ld-loongarch-elf/anno-sym.s b/ld/testsuite/ld-loongarch-elf/anno-sym.s
new file mode 100644
index 00000000..92016a80
--- /dev/null
+++ b/ld/testsuite/ld-loongarch-elf/anno-sym.s
@@ -0,0 +1,13 @@
+	.text
+
+	.hidden .annobin_hello.c
+	.type .annobin_hello.c, STT_NOTYPE
+	.equiv .annobin_hello.c, .
+	.size .annobin_hello.c, 0
+
+	.global _start
+_start:
+	.nop
+	.align 4
+	.dc.a foo
+
diff --git a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
index 1fc70d0a..b43a518a 100644
--- a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
+++ b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
@@ -32,6 +32,7 @@ if [istarget "loongarch64-*-*"] {
     run_dump_test "syscall"
     run_dump_test "disas-jirl"
     run_dump_test "local-ifunc-reloc"
+    run_dump_test "anno-sym"
 }
 
 if [istarget "loongarch32-*-*"] {
diff --git a/ld/testsuite/ld-loongarch-elf/relax-align.dd b/ld/testsuite/ld-loongarch-elf/relax-align.dd
index 5fce2255..37fdab18 100644
--- a/ld/testsuite/ld-loongarch-elf/relax-align.dd
+++ b/ld/testsuite/ld-loongarch-elf/relax-align.dd
@@ -1,7 +1,8 @@
 #...
 .*pcaddi.*
-.*pcaddi.*
 .*nop.*
+.*pcaddi.*
 .*nop.*
-.*0:.*pcaddi.*
+.*pcaddi.*
+.*pcaddi.*
 #pass
diff --git a/ld/testsuite/ld-loongarch-elf/relax-align.s b/ld/testsuite/ld-loongarch-elf/relax-align.s
index 9617c02d..66dfea8f 100644
--- a/ld/testsuite/ld-loongarch-elf/relax-align.s
+++ b/ld/testsuite/ld-loongarch-elf/relax-align.s
@@ -4,6 +4,9 @@
   .text
 L1:
   la.local $a0, L1
+  .align 3
   la.local $a0, L1
-  .align 4
+  .align 3, ,4
+  la.local $a0, L1
+  .align 3, ,2
   la.local $a0, L1
diff --git a/ld/testsuite/ld-loongarch-elf/relax.exp b/ld/testsuite/ld-loongarch-elf/relax.exp
index 24d79ed5..77323d8d 100644
--- a/ld/testsuite/ld-loongarch-elf/relax.exp
+++ b/ld/testsuite/ld-loongarch-elf/relax.exp
@@ -121,7 +121,7 @@ if [istarget loongarch64-*-*] {
 	  [list \
 	      "loongarch relax-align" \
 	      "-e 0x0 -z relro" "" \
-	      "" \
+	      "--no-warn" \
 	      {relax-align.s} \
 	      [list \
 		  [list objdump -d relax-align.dd] \
-- 
2.33.0