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* config/tc-mips.c (mips16_extended_frag): Avoid an infinite loop

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when extending because the value is exactly maxtiny + 1.
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Ian Lance Taylor 1996-12-09 23:34:20 +00:00
parent 8728fa9263
commit 559c664adb
2 changed files with 27 additions and 2 deletions
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3
gas/ChangeLog
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@ -1,5 +1,8 @@
Mon Dec 9 17:09:42 1996 Ian Lance Taylor <ian@cygnus.com>
* config/tc-mips.c (mips16_extended_frag): Avoid an infinite loop
when extending because the value is exactly maxtiny + 1.
* config/tc-mips.c (RELAX_MIPS16_ENCODE): Add small and ext
arguments, and store them. Adjust other RELAX_MIPS16 macros.
(RELAX_MIPS16_USER_SMALL): Define.

26
gas/config/tc-mips.c
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@ -9154,8 +9154,30 @@ mips16_extended_frag (fragp, sec, stretch)
/* If any of the shifted bits are set, we must use an extended
opcode. If the address depends on the size of this
instruction, this can lead to a loop, so we arrange to always
use an extended opcode. */
if ((val & ((1 << op->shift) - 1)) != 0)
use an extended opcode. We only check this when we are in
the main relaxation loop, when SEC is NULL. */
if ((val & ((1 << op->shift) - 1)) != 0 && sec == NULL)
{
fragp->fr_subtype =
RELAX_MIPS16_MARK_LONG_BRANCH (fragp->fr_subtype);
return 1;
}
/* If we are about to mark a frag as extended because the value
is precisely maxtiny + 1, then there is a chance of an
infinite loop as in the following code:
la $4,foo
.skip 1020
.align 2
foo:
In this case when the la is extended, foo is 0x3fc bytes
away, so the la can be shrunk, but then foo is 0x400 away, so
the la must be extended. To avoid this loop, we mark the
frag as extended if it was small, and is about to become
extended with a value of maxtiny + 1. */
if (val == ((maxtiny + 1) << op->shift)
&& ! RELAX_MIPS16_EXTENDED (fragp->fr_subtype)
&& sec == NULL)
{
fragp->fr_subtype =
RELAX_MIPS16_MARK_LONG_BRANCH (fragp->fr_subtype);