varasm: Fix up constpool alias handling [PR99872]

Last year, I have added in r11-2944-g0106300f6c3f7bae5eb1c46dbd45aa07c94e1b15
(aka PR54201 fix) code to find bitwise duplicates in constant pool and output
them as aliases instead of duplicating the data.

Unfortunately this broke mingw32 -m32.
On most targets, ASM_GENERATE_INTERNAL_LABEL with "LC" emits something like
*.LC123 and the targets don't add user label prefixes, so the aliases
that we print should be something like
        .set    .LC5, .LC6
or
        .set    .LC5, .LC6 + 8
and I wasn't sure if ASM_OUTPUT_DEF can handle the * and therefore I have
stripped it.
But, on mingw32 -m32, ASM_GENERATE_INTERNAL_LABEL with "LC" emits
*LC123 and the target has user label prefixes, which means what I wrote
results in
LC6:
        ...
        .set    _LC5, _LC6
which results in unresolved symbols.  I went through the ASM_OUTPUT_DEF
definitions of all targets and all of them use assemble_name twice under
the hood (with various differences on what they print before, in between or
after those names).  And assemble_name handles the name encoding properly,
so if we pass it ASM_OUTPUT_DEF (..., "*.LC123", "*.LC456+16") it will
emit .LC123 and .LC456+16 and if we pass it "*LC789", it will emit
LC789.

2021-04-07  Jakub Jelinek  <jakub@redhat.com>

	PR target/99872
	* varasm.c (output_constant_pool_contents): Don't strip name encoding
	from XSTR (desc->sym, 0) or from label before passing those to
	ASM_OUTPUT_DEF.

diff --git a/gcc/varasm.c b/gcc/varasm.c
index 8112122..8bb921f 100644 (file)
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -4290,13 +4290,13 @@ output_constant_pool_contents (struct rtx_constant_pool *pool)
     if (desc->mark < 0)
       {
 #ifdef ASM_OUTPUT_DEF
-       const char *name = targetm.strip_name_encoding (XSTR (desc->sym, 0));
+       const char *name = XSTR (desc->sym, 0);
        char label[256];
        char buffer[256 + 32];
        const char *p;
 
        ASM_GENERATE_INTERNAL_LABEL (label, "LC", ~desc->mark);
-       p = targetm.strip_name_encoding (label);
+       p = label;
        if (desc->offset)
          {
            sprintf (buffer, "%s+%ld", p, (long) (desc->offset));