From 4989adac848eb8f2fee8b98d9615d2fded22623b Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Wed, 21 Sep 2016 16:51:00 +0100 Subject: [PATCH] [AArch64][SVE 13/32] Add an F_STRICT flag SVE predicate operands can appear in three forms: 1. unsuffixed: "Pn" 2. with a predication type: "Pn/[ZM]" 3. with a size suffix: "Pn.[BHSD]" No variation is allowed: unsuffixed operands cannot have a (redundant) suffix, and the suffixes can never be dropped. Unsuffixed Pn are used in LDR and STR, but they are also used for Pg operands in cases where the result is scalar and where there is therefore no choice to be made between "merging" and "zeroing". This means that some Pg operands have suffixes and others don't. It would be possible to use context-sensitive parsing to handle this difference. The tc-aarch64.c code would then raise an error if the wrong kind of suffix is used for a particular instruction. However, we get much more user-friendly error messages if we parse all three forms for all SVE instructions and record the suffix as a qualifier. The normal qualifier matching code can then report cases where the wrong kind of suffix is used. This is a slight extension of existing usage, which really only checks for the wrong choice of suffix within a particular kind of suffix. The only catch is a that a "NIL" entry in the qualifier list specifically means "no suffix should be present" (case 1 above). NIL isn't a wildcard here. It also means that an instruction that requires all-NIL qualifiers can fail to match (because a suffix was supplied when it shouldn't have been); this requires a slight change to find_best_match. This patch adds an F_STRICT flag to select this behaviour. The flag will be set for all SVE instructions. The behaviour for other instructions doesn't change. include/ * opcode/aarch64.h (F_STRICT): New flag. opcodes/ * aarch64-opc.c (match_operands_qualifier): Handle F_STRICT. gas/ * config/tc-aarch64.c (find_best_match): Simplify, allowing an instruction with all-NIL qualifiers to fail to match. --- gas/ChangeLog | 5 +++++ gas/config/tc-aarch64.c | 5 +---- include/ChangeLog | 4 ++++ include/opcode/aarch64.h | 4 +++- opcodes/ChangeLog | 4 ++++ opcodes/aarch64-opc.c | 11 ++++++++++- 6 files changed, 27 insertions(+), 6 deletions(-) diff --git a/gas/ChangeLog b/gas/ChangeLog index d7df100d64..ac9d359cd7 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,8 @@ +2016-09-21 Richard Sandiford + + * config/tc-aarch64.c (find_best_match): Simplify, allowing an + instruction with all-NIL qualifiers to fail to match. + 2016-09-21 Richard Sandiford * config/tc-aarch64.c (parse_address_main): Remove reloc and diff --git a/gas/config/tc-aarch64.c b/gas/config/tc-aarch64.c index f82fdb9645..f50de702c9 100644 --- a/gas/config/tc-aarch64.c +++ b/gas/config/tc-aarch64.c @@ -4134,7 +4134,7 @@ find_best_match (const aarch64_inst *instr, } max_num_matched = 0; - idx = -1; + idx = 0; /* For each pattern. */ for (i = 0; i < AARCH64_MAX_QLF_SEQ_NUM; ++i, ++qualifiers_list) @@ -4146,9 +4146,6 @@ find_best_match (const aarch64_inst *instr, if (empty_qualifier_sequence_p (qualifiers) == TRUE) { DEBUG_TRACE_IF (i == 0, "empty list of qualifier sequence"); - if (i != 0 && idx == -1) - /* If nothing has been matched, return the 1st sequence. */ - idx = 0; break; } diff --git a/include/ChangeLog b/include/ChangeLog index 2c922c4e73..21ddbfdd82 100644 --- a/include/ChangeLog +++ b/include/ChangeLog @@ -1,3 +1,7 @@ +2016-09-21 Richard Sandiford + + * opcode/aarch64.h (F_STRICT): New flag. + 2016-09-07 Richard Earnshaw * opcode/arm.h (ARM_ARCH_V8A_CRC): New architecture. diff --git a/include/opcode/aarch64.h b/include/opcode/aarch64.h index 1e38749c30..24a2ddbdc0 100644 --- a/include/opcode/aarch64.h +++ b/include/opcode/aarch64.h @@ -598,7 +598,9 @@ extern aarch64_opcode aarch64_opcode_table[]; #define F_OD(X) (((X) & 0x7) << 24) /* Instruction has the field of 'sz'. */ #define F_LSE_SZ (1 << 27) -/* Next bit is 28. */ +/* Require an exact qualifier match, even for NIL qualifiers. */ +#define F_STRICT (1ULL << 28) +/* Next bit is 29. */ static inline bfd_boolean alias_opcode_p (const aarch64_opcode *opcode) diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog index b47f034144..c12ea3a9d4 100644 --- a/opcodes/ChangeLog +++ b/opcodes/ChangeLog @@ -1,3 +1,7 @@ +2016-09-21 Richard Sandiford + + * aarch64-opc.c (match_operands_qualifier): Handle F_STRICT. + 2016-09-21 Richard Sandiford * aarch64-gen.c (indented_print): Avoid hard-coded indentation limit. diff --git a/opcodes/aarch64-opc.c b/opcodes/aarch64-opc.c index 322b991a4b..d870fd6203 100644 --- a/opcodes/aarch64-opc.c +++ b/opcodes/aarch64-opc.c @@ -854,7 +854,7 @@ aarch64_find_best_match (const aarch64_inst *inst, static int match_operands_qualifier (aarch64_inst *inst, bfd_boolean update_p) { - int i; + int i, nops; aarch64_opnd_qualifier_seq_t qualifiers; if (!aarch64_find_best_match (inst, inst->opcode->qualifiers_list, -1, @@ -864,6 +864,15 @@ match_operands_qualifier (aarch64_inst *inst, bfd_boolean update_p) return 0; } + if (inst->opcode->flags & F_STRICT) + { + /* Require an exact qualifier match, even for NIL qualifiers. */ + nops = aarch64_num_of_operands (inst->opcode); + for (i = 0; i < nops; ++i) + if (inst->operands[i].qualifier != qualifiers[i]) + return FALSE; + } + /* Update the qualifiers. */ if (update_p == TRUE) for (i = 0; i < AARCH64_MAX_OPND_NUM; ++i)