diff options
Diffstat (limited to 'gas/config/tc-sparc.c')
| -rw-r--r-- | gas/config/tc-sparc.c | 56 |
1 files changed, 45 insertions, 11 deletions
diff --git a/gas/config/tc-sparc.c b/gas/config/tc-sparc.c index fb3e9fe..2fb3c5a 100644 --- a/gas/config/tc-sparc.c +++ b/gas/config/tc-sparc.c @@ -90,10 +90,15 @@ static int warn_on_bump; architecture, issue a warning. */ static enum sparc_opcode_arch_val warn_after_architecture; -/* Non-zero if as should generate error if an undeclared g[23] register - has been used in -64. */ +/* Non-zero if the assembler should generate error if an undeclared + g[23] register has been used in -64. */ static int no_undeclared_regs; +/* Non-zero if the assembler should generate a warning if an + unpredictable DCTI (delayed control transfer instruction) couple is + found. */ +static int dcti_couples_detect; + /* Non-zero if we should try to relax jumps and calls. */ static int sparc_relax; @@ -484,6 +489,8 @@ struct option md_longopts[] = { {"relax", no_argument, NULL, OPTION_RELAX}, #define OPTION_NO_RELAX (OPTION_MD_BASE + 15) {"no-relax", no_argument, NULL, OPTION_NO_RELAX}, +#define OPTION_DCTI_COUPLES_DETECT (OPTION_MD_BASE + 16) + {"dcti-couples-detect", no_argument, NULL, OPTION_DCTI_COUPLES_DETECT}, {NULL, no_argument, NULL, 0} }; @@ -667,6 +674,10 @@ md_parse_option (int c, const char *arg) sparc_relax = 0; break; + case OPTION_DCTI_COUPLES_DETECT: + dcti_couples_detect = 1; + break; + default: return 0; } @@ -744,6 +755,7 @@ md_show_usage (FILE *stream) appropriate .register directive (default)\n\ -no-undeclared-regs force error on application global register usage\n\ without appropriate .register directive\n\ +--dcti-couples-detect warn when an unpredictable DCTI couple is found\n\ -q ignored\n\ -Qy, -Qn ignored\n\ -s ignored\n")); @@ -1570,16 +1582,38 @@ md_assemble (char *str) if (insn == NULL) return; - /* We warn about attempts to put a floating point branch in a delay slot, - unless the delay slot has been annulled. */ + /* Certain instructions may not appear on delay slots. Check for + these situations. */ if (last_insn != NULL - && (insn->flags & F_FBR) != 0 - && (last_insn->flags & F_DELAYED) != 0 - /* ??? This test isn't completely accurate. We assume anything with - F_{UNBR,CONDBR,FBR} set is annullable. */ - && ((last_insn->flags & (F_UNBR | F_CONDBR | F_FBR)) == 0 - || (last_opcode & ANNUL) == 0)) - as_warn (_("FP branch in delay slot")); + && (last_insn->flags & F_DELAYED) != 0) + { + /* Before SPARC V9 the effect of having a delayed branch + instruction in the delay slot of a conditional delayed branch + was undefined. + + In SPARC V9 DCTI couples are well defined. + + However, starting with the UltraSPARC Architecture 2005, DCTI + couples (of all kind) are deprecated and should not be used, + as they may be slow or behave differently to what the + programmer expects. */ + if (dcti_couples_detect + && (insn->flags & F_DELAYED) != 0 + && ((max_architecture < SPARC_OPCODE_ARCH_V9 + && (last_insn->flags & F_CONDBR) != 0) + || max_architecture >= SPARC_OPCODE_ARCH_V9C)) + as_warn (_("unpredictable DCTI couple")); + + + /* We warn about attempts to put a floating point branch in a + delay slot, unless the delay slot has been annulled. */ + if ((insn->flags & F_FBR) != 0 + /* ??? This test isn't completely accurate. We assume anything with + F_{UNBR,CONDBR,FBR} set is annullable. */ + && ((last_insn->flags & (F_UNBR | F_CONDBR | F_FBR)) == 0 + || (last_opcode & ANNUL) == 0)) + as_warn (_("FP branch in delay slot")); + } /* SPARC before v9 requires a nop instruction between a floating point instruction and a floating point branch. We insert one |