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authorMaciej W. Rozycki <macro@linux-mips.org>2012-03-01 22:37:51 +0000
committerMaciej W. Rozycki <macro@linux-mips.org>2012-03-01 22:37:51 +0000
commita385295e2c80123b85dab47754e049e418925484 (patch)
treec21e950769ad0845c2fdbb1990a1f6783685a6fe /gdb/mips-tdep.c
parent1faeff088bbbd037d7769d214378b4faf805fa2e (diff)
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* mips-tdep.c (mips32_bc1_pc): New function.
(mips32_next_pc): Handle BC1ANY2F, BC1ANY2T, BC1ANY4F, BC1ANY4T, BPOSGE32 and BPOSGE64 instructions. (deal_with_atomic_sequence): Likewise. (mips32_instruction_has_delay_slot): Likewise.
Diffstat (limited to 'gdb/mips-tdep.c')
-rw-r--r--gdb/mips-tdep.c105
1 files changed, 85 insertions, 20 deletions
diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c
index 3e09d5c..bf396f9 100644
--- a/gdb/mips-tdep.c
+++ b/gdb/mips-tdep.c
@@ -1132,6 +1132,36 @@ mips32_relative_offset (ULONGEST inst)
return ((itype_immediate (inst) ^ 0x8000) - 0x8000) << 2;
}
+/* Determine the address of the next instruction executed after the INST
+ floating condition branch instruction at PC. COUNT specifies the
+ number of the floating condition bits tested by the branch. */
+
+static CORE_ADDR
+mips32_bc1_pc (struct gdbarch *gdbarch, struct frame_info *frame,
+ ULONGEST inst, CORE_ADDR pc, int count)
+{
+ int fcsr = mips_regnum (gdbarch)->fp_control_status;
+ int cnum = (itype_rt (inst) >> 2) & (count - 1);
+ int tf = itype_rt (inst) & 1;
+ int mask = (1 << count) - 1;
+ ULONGEST fcs;
+ int cond;
+
+ if (fcsr == -1)
+ /* No way to handle; it'll most likely trap anyway. */
+ return pc;
+
+ fcs = get_frame_register_unsigned (frame, fcsr);
+ cond = ((fcs >> 24) & 0xfe) | ((fcs >> 23) & 0x01);
+
+ if (((cond >> cnum) & mask) != mask * !tf)
+ pc += mips32_relative_offset (inst);
+ else
+ pc += 4;
+
+ return pc;
+}
+
/* Determine where to set a single step breakpoint while considering
branch prediction. */
static CORE_ADDR
@@ -1164,20 +1194,15 @@ mips32_next_pc (struct frame_info *frame, CORE_ADDR pc)
}
else if (itype_op (inst) == 17 && itype_rs (inst) == 8)
/* BC1F, BC1FL, BC1T, BC1TL: 010001 01000 */
- {
- int tf = itype_rt (inst) & 0x01;
- int cnum = itype_rt (inst) >> 2;
- int fcrcs =
- get_frame_register_signed (frame,
- mips_regnum (get_frame_arch (frame))->
- fp_control_status);
- int cond = ((fcrcs >> 24) & 0xfe) | ((fcrcs >> 23) & 0x01);
-
- if (((cond >> cnum) & 0x01) == tf)
- pc += mips32_relative_offset (inst) + 4;
- else
- pc += 8;
- }
+ pc = mips32_bc1_pc (gdbarch, frame, inst, pc + 4, 1);
+ else if (itype_op (inst) == 17 && itype_rs (inst) == 9
+ && (itype_rt (inst) & 2) == 0)
+ /* BC1ANY2F, BC1ANY2T: 010001 01001 xxx0x */
+ pc = mips32_bc1_pc (gdbarch, frame, inst, pc + 4, 2);
+ else if (itype_op (inst) == 17 && itype_rs (inst) == 10
+ && (itype_rt (inst) & 2) == 0)
+ /* BC1ANY4F, BC1ANY4T: 010001 01010 xxx0x */
+ pc = mips32_bc1_pc (gdbarch, frame, inst, pc + 4, 4);
else
pc += 4; /* Not a branch, next instruction is easy. */
}
@@ -1236,6 +1261,25 @@ mips32_next_pc (struct frame_info *frame, CORE_ADDR pc)
else
pc += 8; /* after the delay slot */
break;
+ case 0x1c: /* BPOSGE32 */
+ case 0x1e: /* BPOSGE64 */
+ pc += 4;
+ if (itype_rs (inst) == 0)
+ {
+ unsigned int pos = (op & 2) ? 64 : 32;
+ int dspctl = mips_regnum (gdbarch)->dspctl;
+
+ if (dspctl == -1)
+ /* No way to handle; it'll most likely trap anyway. */
+ break;
+
+ if ((get_frame_register_unsigned (frame,
+ dspctl) & 0x7f) >= pos)
+ pc += mips32_relative_offset (inst);
+ else
+ pc += 4;
+ }
+ break;
/* All of the other instructions in the REGIMM category */
default:
pc += 4;
@@ -2618,7 +2662,9 @@ deal_with_atomic_sequence (struct gdbarch *gdbarch,
return 0; /* fallback to the standard single-step code. */
break;
case 1: /* REGIMM */
- is_branch = ((itype_rt (insn) & 0xc) == 0); /* B{LT,GE}Z* */
+ is_branch = ((itype_rt (insn) & 0xc) == 0 /* B{LT,GE}Z* */
+ || ((itype_rt (insn) & 0x1e) == 0
+ && itype_rs (insn) == 0)); /* BPOSGE* */
break;
case 2: /* J */
case 3: /* JAL */
@@ -2634,6 +2680,11 @@ deal_with_atomic_sequence (struct gdbarch *gdbarch,
is_branch = 1;
break;
case 17: /* COP1 */
+ is_branch = ((itype_rs (insn) == 9 || itype_rs (insn) == 10)
+ && (itype_rt (insn) & 0x2) == 0);
+ if (is_branch) /* BC1ANY2F, BC1ANY2T, BC1ANY4F, BC1ANY4T */
+ break;
+ /* Fall through. */
case 18: /* COP2 */
case 19: /* COP3 */
is_branch = (itype_rs (insn) == 8); /* BCzF, BCzFL, BCzT, BCzTL */
@@ -5333,6 +5384,8 @@ mips32_instruction_has_delay_slot (struct gdbarch *gdbarch, CORE_ADDR addr)
unsigned long inst;
int status;
int op;
+ int rs;
+ int rt;
status = target_read_memory (addr, buf, MIPS_INSN32_SIZE);
if (status)
@@ -5341,10 +5394,19 @@ mips32_instruction_has_delay_slot (struct gdbarch *gdbarch, CORE_ADDR addr)
inst = mips_fetch_instruction (gdbarch, addr);
op = itype_op (inst);
if ((inst & 0xe0000000) != 0)
- return (op >> 2 == 5 /* BEQL, BNEL, BLEZL, BGTZL: bits 0101xx */
- || op == 29 /* JALX: bits 011101 */
- || (op == 17 && itype_rs (inst) == 8));
+ {
+ rs = itype_rs (inst);
+ rt = itype_rt (inst);
+ return (op >> 2 == 5 /* BEQL, BNEL, BLEZL, BGTZL: bits 0101xx */
+ || op == 29 /* JALX: bits 011101 */
+ || (op == 17
+ && (rs == 8
/* BC1F, BC1FL, BC1T, BC1TL: 010001 01000 */
+ || (rs == 9 && (rt & 0x2) == 0)
+ /* BC1ANY2F, BC1ANY2T: bits 010001 01001 */
+ || (rs == 10 && (rt & 0x2) == 0))));
+ /* BC1ANY4F, BC1ANY4T: bits 010001 01010 */
+ }
else
switch (op & 0x07) /* extract bits 28,27,26 */
{
@@ -5354,10 +5416,13 @@ mips32_instruction_has_delay_slot (struct gdbarch *gdbarch, CORE_ADDR addr)
|| op == 9); /* JALR */
break; /* end SPECIAL */
case 1: /* REGIMM */
- op = itype_rt (inst); /* branch condition */
- return (op & 0xc) == 0;
+ rs = itype_rs (inst);
+ rt = itype_rt (inst); /* branch condition */
+ return ((rt & 0xc) == 0
/* BLTZ, BLTZL, BGEZ, BGEZL: bits 000xx */
/* BLTZAL, BLTZALL, BGEZAL, BGEZALL: 100xx */
+ || ((rt & 0x1e) == 0x1c && rs == 0));
+ /* BPOSGE32, BPOSGE64: bits 1110x */
break; /* end REGIMM */
default: /* J, JAL, BEQ, BNE, BLEZ, BGTZ */
return 1;