* alpha-tdep.c (fp_register_zero_p): New function.

(fp_register_sign_bit): New function.
        (alpha_next_pc): Add support for floating-point control instructions.
This commit is contained in:
Joel Brobecker 2005-05-20 06:56:00 +00:00
parent 28e99bb619
commit 0de94d4be4
2 changed files with 60 additions and 2 deletions

View File

@ -1,3 +1,9 @@
2005-05-20 Joel Brobecker <brobecker@adacore.com>
* alpha-tdep.c (fp_register_zero_p): New function.
(fp_register_sign_bit): New function.
(alpha_next_pc): Add support for floating-point control instructions.
2005-05-19 Andrew Cagney <cagney@gnu.org>
* defs.h (extract_signed_integer, extract_unsigned_integer)

View File

@ -1335,6 +1335,30 @@ alpha_fill_fp_regs (int regno, void *f0_f30, void *fpcr)
}
/* Return nonzero if the G_floating register value in REG is equal to
zero for FP control instructions. */
static int
fp_register_zero_p (LONGEST reg)
{
/* Check that all bits except the sign bit are zero. */
const LONGEST zero_mask = ((LONGEST) 1 << 63) ^ -1;
return ((reg & zero_mask) == 0);
}
/* Return the value of the sign bit for the G_floating register
value held in REG. */
static int
fp_register_sign_bit (LONGEST reg)
{
const LONGEST sign_mask = (LONGEST) 1 << 63;
return ((reg & sign_mask) != 0);
}
/* alpha_software_single_step() is called just before we want to resume
the inferior, if we want to single-step it but there is no hardware
or kernel single-step support (NetBSD on Alpha, for example). We find
@ -1350,6 +1374,7 @@ alpha_next_pc (CORE_ADDR pc)
unsigned int op;
int offset;
LONGEST rav;
char reg[8];
insn = alpha_read_insn (pc);
@ -1379,7 +1404,9 @@ alpha_next_pc (CORE_ADDR pc)
}
/* Need to determine if branch is taken; read RA. */
rav = (LONGEST) read_register ((insn >> 21) & 0x1f);
regcache_cooked_read (current_regcache, (insn >> 21) & 0x1f, reg);
rav = extract_signed_integer (reg, 8);
switch (op)
{
case 0x38: /* BLBC */
@ -1415,7 +1442,32 @@ alpha_next_pc (CORE_ADDR pc)
goto branch_taken;
break;
/* ??? Missing floating-point branches. */
/* Floating point branches. */
case 0x31: /* FBEQ */
if (fp_register_zero_p (rav))
goto branch_taken;
break;
case 0x36: /* FBGE */
if (fp_register_sign_bit (rav) == 0 || fp_register_zero_p (rav))
goto branch_taken;
break;
case 0x37: /* FBGT */
if (fp_register_sign_bit (rav) == 0 && ! fp_register_zero_p (rav))
goto branch_taken;
break;
case 0x33: /* FBLE */
if (fp_register_sign_bit (rav) == 1 || fp_register_zero_p (rav))
goto branch_taken;
break;
case 0x32: /* FBLT */
if (fp_register_sign_bit (rav) == 1 && ! fp_register_zero_p (rav))
goto branch_taken;
break;
case 0x35: /* FBNE */
if (! fp_register_zero_p (rav))
goto branch_taken;
break;
}
}