@@ -128,6 +128,11 @@ static bool call36 = 0;
#define RELAX_BRANCH_ENCODE(x) \
(BFD_RELOC_LARCH_B16 == (x) ? RELAX_BRANCH_16 : RELAX_BRANCH_21)
+#define ALIGN_MAX_ADDEND(n, max) ((max << 8) | n)
+#define ALIGN_MAX_NOP_BYTES(addend) ((1 << (addend & 0xff)) - 4)
+#define FRAG_AT_START_OF_SECTION(frag) \
+ (0 == frag->fr_address && 0 == frag->fr_fix)
+
enum options
{
OPTION_IGNORE = OPTION_MD_BASE,
@@ -1647,10 +1652,32 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
}
}
+/* Estimate the size of a frag before relaxing. */
+
int
-md_estimate_size_before_relax (fragS *fragp ATTRIBUTE_UNUSED,
- asection *segtype ATTRIBUTE_UNUSED)
+md_estimate_size_before_relax (fragS *fragp, asection *sec)
{
+ /* align pseudo instunctions. */
+ if (rs_align_code == fragp->fr_subtype)
+ {
+ offsetT nop_bytes;
+ if (NULL == fragp->fr_symbol)
+ nop_bytes = fragp->fr_offset;
+ else
+ nop_bytes = ALIGN_MAX_NOP_BYTES (fragp->fr_offset);
+
+ /* Normally, nop_bytes should be >= 4. */
+ gas_assert (nop_bytes > 0);
+
+ if (FRAG_AT_START_OF_SECTION (fragp)
+ && 0 == ((1 << sec->alignment_power) % (nop_bytes + 4)))
+ return (fragp->fr_var = 0);
+ else
+ return (fragp->fr_var = nop_bytes);
+ }
+
+ /* branch instructions and other instructions.
+ branch instructions may become 8 bytes after relaxing. */
return (fragp->fr_var = 4);
}
@@ -1767,8 +1794,7 @@ bool
loongarch_frag_align_code (int n, int max)
{
char *nops;
- symbolS *s;
- expressionS ex;
+ symbolS *s = NULL;
bfd_vma insn_alignment = 4;
bfd_vma bytes = (bfd_vma) 1 << n;
@@ -1783,8 +1809,6 @@ loongarch_frag_align_code (int n, int max)
if (!LARCH_opts.relax)
return false;
- nops = frag_more (worst_case_bytes);
-
/* If max <= 0, ignore max.
If max >= worst_case_bytes, max has no effect.
Similar to gas/write.c relax_segment function rs_align_code case:
@@ -1795,21 +1819,22 @@ loongarch_frag_align_code (int n, int max)
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;
- }
- else
- {
- ex.X_op = O_constant;
- ex.X_add_number = worst_case_bytes;
}
+ frag_grow (worst_case_bytes);
+ /* Use relaxable frag for .align.
+ If .align at the start of section, do nothing. Section alignment can
+ ensure correct alignment.
+ If .align is not at the start of a section, reserve NOP instructions
+ and R_LARCH_ALIGN relocation. */
+ nops = frag_var (rs_machine_dependent, worst_case_bytes, worst_case_bytes,
+ rs_align_code, s,
+ s ? (bfd_vma) ALIGN_MAX_ADDEND (n, max) : worst_case_bytes,
+ NULL);
+
+ /* Default write NOP for aligned bytes. */
loongarch_make_nops (nops, worst_case_bytes);
- fix_new_exp (frag_now, nops - frag_now->fr_literal, 0,
- &ex, false, BFD_RELOC_LARCH_ALIGN);
-
/* We need to start a new frag after the alignment which may be removed by
the linker, to prevent the assembler from computing static offsets.
This is necessary to get correct EH info. */
@@ -1966,8 +1991,7 @@ loongarch_relaxed_branch_length (fragS *fragp, asection *sec, int update)
}
int
-loongarch_relax_frag (asection *sec ATTRIBUTE_UNUSED,
- fragS *fragp ATTRIBUTE_UNUSED,
+loongarch_relax_frag (asection *sec, fragS *fragp,
long stretch ATTRIBUTE_UNUSED)
{
if (RELAX_BRANCH (fragp->fr_subtype))
@@ -1976,6 +2000,27 @@ loongarch_relax_frag (asection *sec ATTRIBUTE_UNUSED,
fragp->fr_var = loongarch_relaxed_branch_length (fragp, sec, true);
return fragp->fr_var - old_var;
}
+ else if (rs_align_code == fragp->fr_subtype)
+ {
+ offsetT nop_bytes;
+ if (NULL == fragp->fr_symbol)
+ nop_bytes = fragp->fr_offset;
+ else
+ nop_bytes = ALIGN_MAX_NOP_BYTES (fragp->fr_offset);
+
+ /* Normally, nop_bytes should be >= 4. */
+ gas_assert (nop_bytes > 0);
+
+ offsetT old_var = fragp->fr_var;
+ /* If .align at the start of a section, do nothing. Section alignment
+ * can ensure correct alignment. */
+ if (FRAG_AT_START_OF_SECTION (fragp)
+ && 0 == ((1 << sec->alignment_power) % (nop_bytes + 4)))
+ fragp->fr_var = 0;
+ else
+ fragp->fr_var = nop_bytes;
+ return fragp->fr_var - old_var;
+ }
return 0;
}
@@ -2051,13 +2096,53 @@ loongarch_convert_frag_branch (fragS *fragp)
fragp->fr_fix += fragp->fr_var;
}
-/* Relax a machine dependent frag. This returns the amount by which
- the current size of the frag should change. */
+/* Relax .align frag. */
+
+static void
+loongarch_convert_frag_align (fragS *fragp, asection *sec)
+{
+ bfd_byte *buf = (bfd_byte *)fragp->fr_literal + fragp->fr_fix;
+
+ offsetT nop_bytes;
+ if (NULL == fragp->fr_symbol)
+ nop_bytes = fragp->fr_offset;
+ else
+ nop_bytes = ALIGN_MAX_NOP_BYTES (fragp->fr_offset);
+
+ /* Normally, nop_bytes should be >= 4. */
+ gas_assert (nop_bytes > 0);
+
+ if (!(FRAG_AT_START_OF_SECTION (fragp)
+ && 0 == ((1 << sec->alignment_power) % (nop_bytes + 4))))
+ {
+ expressionS exp;
+ exp.X_op = O_symbol;
+ exp.X_add_symbol = fragp->fr_symbol;
+ exp.X_add_number = fragp->fr_offset;
+
+ fixS *fixp = fix_new_exp (fragp, buf - (bfd_byte *)fragp->fr_literal,
+ nop_bytes, &exp, false, BFD_RELOC_LARCH_ALIGN);
+ fixp->fx_file = fragp->fr_file;
+ fixp->fx_line = fragp->fr_line;
+
+ buf += nop_bytes;
+ }
+
+ gas_assert (buf == (bfd_byte *)fragp->fr_literal
+ + fragp->fr_fix + fragp->fr_var);
+
+ fragp->fr_fix += fragp->fr_var;
+}
+
+/* Relax a machine dependent frag. */
void
-md_convert_frag (bfd *abfd ATTRIBUTE_UNUSED, segT asec ATTRIBUTE_UNUSED,
- fragS *fragp)
+md_convert_frag (bfd *abfd ATTRIBUTE_UNUSED, segT asec, fragS *fragp)
{
- gas_assert (RELAX_BRANCH (fragp->fr_subtype));
- loongarch_convert_frag_branch (fragp);
+ gas_assert (RELAX_BRANCH (fragp->fr_subtype)
+ || rs_align_code == fragp->fr_subtype);
+ if (RELAX_BRANCH (fragp->fr_subtype))
+ loongarch_convert_frag_branch (fragp);
+ else if (rs_align_code == fragp->fr_subtype)
+ loongarch_convert_frag_align (fragp, asec);
}
new file mode 100644
@@ -0,0 +1,12 @@
+#as:
+#objdump: -dr
+
+.*:[ ]+file format .*
+
+
+Disassembly of section .text:
+0* <.text>:
+[ ]+0:[ ]+4c000020[ ]+ret
+Disassembly of section abc:
+0* <abc>:
+[ ]+0:[ ]+4c000020[ ]+ret
new file mode 100644
@@ -0,0 +1,7 @@
+.text
+.align 3
+ret
+
+.section "abc", "ax"
+.align 4, ,4
+ret
new file mode 100644
@@ -0,0 +1,15 @@
+#ld: -e0
+#objdump: -d
+
+.*:[ ]+file format .*
+
+
+Disassembly of section aaa:
+0000000120000078 <aaa>:
+[ ]+120000078:[ ]+4c000020[ ]+ret
+Disassembly of section bbb:
+0000000120000080 <bbb>:
+[ ]+120000080:[ ]+4c000020[ ]+ret
+Disassembly of section ccc:
+0000000120000090 <__bss_start-0x4004>:
+[ ]+120000090:[ ]+4c000020[ ]+ret
new file mode 100644
@@ -0,0 +1,13 @@
+# If .align at the start of a section, do not add NOP instructions
+# and do not emit R_LARCH_ALIGN relocations.
+# Section alignment can ensure correct alignment.
+.section "aaa", "ax"
+ret
+
+.section "bbb", "ax"
+.align 3
+ret
+
+.section "ccc", "ax"
+.align 4, ,4
+ret
@@ -20,6 +20,7 @@
#
if [istarget loongarch64-*-*] {
+ run_dump_test "relax-align-first"
if [isbuild loongarch64-*-*] {
set testname "loongarch relax .exe build"