+Tue Nov 17 11:17:06 1992 Ian Lance Taylor (ian@cygnus.com)
+
+ * tm-rs6000.h (BELIEVE_PCC_PROMOTION): Define, since AIX cc gets
+ it right.
+ (aix_framedata): added nosavedpc field.
+ (SAVED_PC_AFTER_CALL): Don't try to optimize; just call
+ read_register.
+ (FRAMELESS_FUNCTION_INVOCATION): Pass second argument of 0.
+ (FRAME_SAVED_PC): If PC not saved, use SAVED_PC_AFTER_CALL.
+ * rs6000-tdep.c (skip_prologue): Handle gcc generated stfd
+ instructions as function_frame_info does. Expand special case of
+ st r31,-4(r1) to be st r31,NUM(r1), since gcc can generate offsets
+ other than -4.
+ (pop_frame): Add 4 rather than sizeof (int) to avoid host
+ dependence.
+ (function_frame_info): Set frameless if the function has no frame,
+ and set nosavedpc if the PC was not saved. Handle gcc generated
+ stfd 31,-4(31); st 31, -12(31) correctly.
+ (frameless_function_invocation): New second argument pcsaved; if 0
+ return whether the function has a frame, if 1 return whether the
+ function saved PC.
+ (frame_initial_stack_address): Correct typo: cache registers for
+ callee_fi, not for fi, (avoids reading garbage memory locations).
+
Mon Nov 16 15:58:07 1992 Stu Grossman (grossman at cygnus.com)
+ * infrun.c (wait_for_inferior (just before step_over_function
+ label)): Change test for stepping into subroutine to check for the
+ presence of line number info. This makes stuff compiled with -g1
+ cause GDB to not lose control when stepping.
+
* symtab.c (find_pc_line): Improve code per gnu's suggestions.
Improve comments as well.
return pc - 4; /* don't skip over this branch */
}
+ if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
+ pc += 4; /* store floating register double */
+ op = read_memory_integer (pc, 4);
+ }
+
if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
pc += 4;
op = read_memory_integer (pc, 4);
while (((tmp = op >> 16) == 0x9001) || /* st r0, NUM(r1) */
(tmp == 0x9421) || /* stu r1, NUM(r1) */
- (op == 0x93e1fffc)) /* st r31,-4(r1) */
+ (tmp == 0x93e1)) /* st r31,NUM(r1) */
{
pc += 4;
op = read_memory_integer (pc, 4);
if (fdata.saved_gpr != -1)
for (ii=fdata.saved_gpr; ii <= 31; ++ii) {
read_memory (addr, ®isters [REGISTER_BYTE (ii)], 4);
- addr += sizeof (int);
+ addr += 4;
}
if (fdata.saved_fpr != -1)
/* return information about a function frame.
in struct aix_frameinfo fdata:
- - frameless is TRUE, if function does not save %pc value in its frame.
+ - frameless is TRUE, if function does not have a frame.
+ - nosavedpc is TRUE, if function does not save %pc value in its frame.
- offset is the number of bytes used in the frame to save registers.
- saved_gpr is the number of the first saved gpr.
- saved_fpr is the number of the first saved fpr.
fdata->offset = 0;
fdata->saved_gpr = fdata->saved_fpr = fdata->alloca_reg = -1;
+ fdata->frameless = 1;
op = read_memory_integer (pc, 4);
if (op == 0x7c0802a6) { /* mflr r0 */
pc += 4;
op = read_memory_integer (pc, 4);
+ fdata->nosavedpc = 0;
fdata->frameless = 0;
}
- else /* else, this is a frameless invocation */
- fdata->frameless = 1;
-
+ else /* else, pc is not saved */
+ fdata->nosavedpc = 1;
if ((op & 0xfc00003e) == 0x7c000026) { /* mfcr Rx */
pc += 4;
op = read_memory_integer (pc, 4);
+ fdata->frameless = 0;
}
if ((op & 0xfc000000) == 0x48000000) { /* bl foo, to save fprs??? */
if (op == 0x4def7b82 || /* crorc 15, 15, 15 */
op == 0x0)
return; /* prologue is over */
+ fdata->frameless = 0;
}
if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */
pc += 4; /* store floating register double */
op = read_memory_integer (pc, 4);
+ fdata->frameless = 0;
}
if ((op & 0xfc1f0000) == 0xbc010000) { /* stm Rx, NUM(r1) */
fdata->saved_gpr = (op >> 21) & 0x1f;
tmp2 = op & 0xffff;
if (tmp2 > 0x7fff)
- tmp2 = 0xffff0000 | tmp2;
+ tmp2 = (~0 &~ 0xffff) | tmp2;
if (tmp2 < 0) {
tmp2 = tmp2 * -1;
fdata->offset = tmp2;
pc += 4;
op = read_memory_integer (pc, 4);
+ fdata->frameless = 0;
}
while (((tmp = op >> 16) == 0x9001) || /* st r0, NUM(r1) */
(tmp == 0x9421) || /* stu r1, NUM(r1) */
- (op == 0x93e1fffc)) /* st r31,-4(r1) */
+ (tmp == 0x93e1)) /* st r31, NUM(r1) */
{
+ int tmp2;
+
/* gcc takes a short cut and uses this instruction to save r31 only. */
- if (op == 0x93e1fffc) {
+ if (tmp == 0x93e1) {
if (fdata->offset)
/* fatal ("Unrecognized prolog."); */
printf ("Unrecognized prolog!\n");
fdata->saved_gpr = 31;
- fdata->offset = 4;
+ tmp2 = op & 0xffff;
+ if (tmp2 > 0x7fff) {
+ tmp2 = - ((~0 &~ 0xffff) | tmp2);
+ fdata->saved_fpr = (tmp2 - ((32 - 31) * 4)) / 8;
+ if ( fdata->saved_fpr > 0)
+ fdata->saved_fpr = 32 - fdata->saved_fpr;
+ else
+ fdata->saved_fpr = -1;
+ }
+ fdata->offset = tmp2;
}
pc += 4;
op = read_memory_integer (pc, 4);
+ fdata->frameless = 0;
}
while ((tmp = (op >> 22)) == 0x20f) { /* l r31, ... or */
pc += 4; /* l r30, ... */
op = read_memory_integer (pc, 4);
+ fdata->frameless = 0;
}
/* store parameters into stack */
{
pc += 4; /* store fpr double */
op = read_memory_integer (pc, 4);
+ fdata->frameless = 0;
}
- if (op == 0x603f0000) /* oril r31, r1, 0x0 */
+ if (op == 0x603f0000) { /* oril r31, r1, 0x0 */
fdata->alloca_reg = 31;
+ fdata->frameless = 0;
+ }
}
/* Determines whether the function FI has a frame on the stack or not.
- Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h. */
+ Called from the FRAMELESS_FUNCTION_INVOCATION macro in tm.h with a
+ second argument of 0, and from the FRAME_SAVED_PC macro with a
+ second argument of 1. */
int
-frameless_function_invocation (fi)
+frameless_function_invocation (fi, pcsaved)
struct frame_info *fi;
+int pcsaved;
{
CORE_ADDR func_start;
struct aix_framedata fdata;
return 0;
function_frame_info (func_start, &fdata);
- return fdata.frameless;
+ return pcsaved ? fdata.nosavedpc : fdata.frameless;
}
for (callee_fi = fi->next; callee_fi; callee_fi = callee_fi->next) {
if (!callee_fi->cache_fsr)
- frame_get_cache_fsr (fi, NULL);
+ frame_get_cache_fsr (callee_fi, NULL);
/* this is the address in which alloca register is saved. */
#define PC_LOAD_SEGMENT(PC) pc_load_segment_name(PC)
+/* AIX cc seems to get this right. */
+
+#define BELIEVE_PCC_PROMOTION 1
/* Conversion between a register number in stab string to actual register num. */
int saved_fpr; /* smallest # of saved fpr */
int alloca_reg; /* alloca register number (frame ptr) */
char frameless; /* true if frameless functions. */
+ char nosavedpc; /* true if pc not saved. */
};
void
the new frame is not set up until the new function executes
some instructions. */
-#define SAVED_PC_AFTER_CALL(frame) \
- (register_valid [LR_REGNUM] ? \
- (*(int*)®isters[REGISTER_BYTE (LR_REGNUM)]) : \
- read_register (LR_REGNUM))
-
-/*#define SAVED_PC_AFTER_CALL(frame) saved_pc_after_call(frame) */
-
+#define SAVED_PC_AFTER_CALL(frame) read_register (LR_REGNUM)
/* Address of end of stack space. */
does not, FRAMELESS is set to 1, else 0. */
#define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
- FRAMELESS = frameless_function_invocation (FI)
+ FRAMELESS = frameless_function_invocation (FI, 0)
/* Functions calling alloca() change the value of the stack pointer. We
need to use initial stack pointer (which is saved in r31 by gcc) in
CORE_ADDR initial_sp; /* initial stack pointer. */ \
struct frame_saved_regs *cache_fsr; /* saved registers */
-/* Frameless function invocation in IBM RS/6000 is half-done. It perfectly
- sets up a new frame, e.g. a new frame (in fact stack) pointer, etc, but it
- doesn't save the %pc. In the following, even though it is considered a
- frameless invocation, we still need to walk one frame up. */
+/* Frameless function invocation in IBM RS/6000 is sometimes
+ half-done. It perfectly sets up a new frame, e.g. a new frame (in
+ fact stack) pointer, etc, but it doesn't save the %pc. We call
+ frameless_function_invocation to tell us how to get the %pc. */
#define INIT_EXTRA_FRAME_INFO(fromleaf, fi) \
fi->initial_sp = 0; \
fi->cache_fsr = 0;
-#define FRAME_SAVED_PC(FRAME) \
- read_memory_integer (read_memory_integer ((FRAME)->frame, 4)+8, 4)
+#define FRAME_SAVED_PC(FRAME) \
+ (frameless_function_invocation (FRAME, 1) \
+ ? SAVED_PC_AFTER_CALL (FRAME) \
+ : read_memory_integer (read_memory_integer ((FRAME)->frame, 4)+8, 4))
#define FRAME_ARGS_ADDRESS(FI) \
(((struct frame_info*)(FI))->initial_sp ? \