diff options
Diffstat (limited to 'gdb')
| -rw-r--r-- | gdb/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/sparc-tdep.c | 70 |
2 files changed, 58 insertions, 17 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index db94468..a1325c6 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2011-05-23 Jerome Guitton <guitton@adacore.com> + + * sparc-tdep.c (sparc_skip_stack_check): Recognize a new instruction + sequence for probing loops. + 2011-05-23 Pedro Alves <pedro@codesourcery.com> * infrun.c (user_visible_resume_ptid): Fix typos in describing diff --git a/gdb/sparc-tdep.c b/gdb/sparc-tdep.c index 84fa3b1e..42c13ac 100644 --- a/gdb/sparc-tdep.c +++ b/gdb/sparc-tdep.c @@ -609,19 +609,46 @@ sparc_skip_stack_check (const CORE_ADDR start_pc) CORE_ADDR pc = start_pc; unsigned long insn; int offset_stack_checking_sequence = 0; + int probing_loop = 0; /* With GCC, all stack checking sequences begin with the same two - instructions. */ + instructions, plus an optional one in the case of a probing loop: - /* sethi <some immediate>,%g1 */ + sethi <some immediate>, %g1 + sub %sp, %g1, %g1 + + or: + + sethi <some immediate>, %g1 + sethi <some immediate>, %g4 + sub %sp, %g1, %g1 + + or: + + sethi <some immediate>, %g1 + sub %sp, %g1, %g1 + sethi <some immediate>, %g4 + + If the optional instruction is found (setting g4), assume that a + probing loop will follow. */ + + /* sethi <some immediate>, %g1 */ insn = sparc_fetch_instruction (pc); pc = pc + 4; if (!(X_OP (insn) == 0 && X_OP2 (insn) == 0x4 && X_RD (insn) == 1)) return start_pc; - /* sub %sp, %g1, %g1 */ + /* optional: sethi <some immediate>, %g4 */ insn = sparc_fetch_instruction (pc); pc = pc + 4; + if (X_OP (insn) == 0 && X_OP2 (insn) == 0x4 && X_RD (insn) == 4) + { + probing_loop = 1; + insn = sparc_fetch_instruction (pc); + pc = pc + 4; + } + + /* sub %sp, %g1, %g1 */ if (!(X_OP (insn) == 2 && X_OP3 (insn) == 0x4 && !X_I(insn) && X_RD (insn) == 1 && X_RS1 (insn) == 14 && X_RS2 (insn) == 1)) return start_pc; @@ -629,6 +656,14 @@ sparc_skip_stack_check (const CORE_ADDR start_pc) insn = sparc_fetch_instruction (pc); pc = pc + 4; + /* optional: sethi <some immediate>, %g4 */ + if (X_OP (insn) == 0 && X_OP2 (insn) == 0x4 && X_RD (insn) == 4) + { + probing_loop = 1; + insn = sparc_fetch_instruction (pc); + pc = pc + 4; + } + /* First possible sequence: [first two instructions above] clr [%g1 - some immediate] */ @@ -680,22 +715,21 @@ sparc_skip_stack_check (const CORE_ADDR start_pc) } /* Third sequence: A probing loop. - [first two instructions above] - sethi <some immediate>, %g4 + [first three instructions above] sub %g1, %g4, %g4 cmp %g1, %g4 be <disp> add %g1, -<some immediate>, %g1 ba <disp> clr [%g1] + + And an optional last probe for the remainder: + clr [%g4 - some immediate] */ - /* sethi <some immediate>, %g4 */ - else if (X_OP (insn) == 0 && X_OP2 (insn) == 0x4 && X_RD (insn) == 4) + if (probing_loop) { /* sub %g1, %g4, %g4 */ - insn = sparc_fetch_instruction (pc); - pc = pc + 4; if (!(X_OP (insn) == 2 && X_OP3 (insn) == 0x4 && !X_I(insn) && X_RD (insn) == 4 && X_RS1 (insn) == 1 && X_RS2 (insn) == 4)) return start_pc; @@ -726,22 +760,24 @@ sparc_skip_stack_check (const CORE_ADDR start_pc) if (!(X_OP (insn) == 0 && X_COND (insn) == 0x8)) return start_pc; - /* clr [%g1] */ + /* clr [%g1] (st %g0, [%g1] or st %g0, [%g1+0]) */ insn = sparc_fetch_instruction (pc); pc = pc + 4; - if (!(X_OP (insn) == 3 && X_OP3(insn) == 0x4 && !X_I(insn) - && X_RD (insn) == 0 && X_RS1 (insn) == 1)) + if (!(X_OP (insn) == 3 && X_OP3(insn) == 0x4 + && X_RD (insn) == 0 && X_RS1 (insn) == 1 + && (!X_I(insn) || X_SIMM13 (insn) == 0))) return start_pc; - /* clr [%g4 - some immediate] */ + /* We found a valid stack-check sequence, return the new PC. */ + + /* optional: clr [%g4 - some immediate] */ insn = sparc_fetch_instruction (pc); pc = pc + 4; if (!(X_OP (insn) == 3 && X_OP3(insn) == 0x4 && X_I(insn) && X_RS1 (insn) == 4 && X_RD (insn) == 0)) - return start_pc; - - /* We found a valid stack-check sequence, return the new PC. */ - return pc; + return pc - 4; + else + return pc; } /* No stack check code in our prologue, return the start_pc. */ |