From 0de94d4be49237e55adfac6861f4580766425f2e Mon Sep 17 00:00:00 2001 From: Joel Brobecker Date: Fri, 20 May 2005 06:56:00 +0000 Subject: [PATCH] * 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. --- gdb/ChangeLog | 6 ++++++ gdb/alpha-tdep.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 60 insertions(+), 2 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 7e3d112..cbf67af 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2005-05-20 Joel Brobecker + + * 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 * defs.h (extract_signed_integer, extract_unsigned_integer) diff --git a/gdb/alpha-tdep.c b/gdb/alpha-tdep.c index 8dc0759..7e3f684 100644 --- a/gdb/alpha-tdep.c +++ b/gdb/alpha-tdep.c @@ -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; } } -- 2.7.4