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Generate an INST_PREDICATES table for each ISA.

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Instead of generating a single `check_instp()` function, create an array
of individual function pointers for checking instruction predicates.

This makes explicit the jump table in the old check_instp() method and
it gives us a way of determining the number of instruction predicates
that exists.
This commit is contained in:
Jakob Stoklund Olesen
2017-07-24 14:13:35 -07:00
parent a31dd3aa7a
commit f643e7e752
8 changed files with 35 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

43
lib/cretonne/meta/gen_encoding.py
View File

@@ -101,36 +101,27 @@ def emit_instp(instp, fmt):
fmt.line('return {};'.format(instp.rust_predicate(0)))
def emit_instps(instps, fmt):
def emit_inst_predicates(instps, fmt):
# type: (Sequence[PredNode], srcgen.Formatter) -> None
"""
Emit a function for matching instruction predicates.
Emit private functions for matching instruction predicates as well as a
static `INST_PREDICATES` array indexed by predicate number.
"""
if not instps:
# If the ISA has no predicates, just emit a stub.
with fmt.indented(
'pub fn check_instp(_: &InstructionData, _: u16) ' +
'-> bool {', '}'):
fmt.line('unimplemented!()')
return
with fmt.indented(
'pub fn check_instp(inst: &InstructionData, instp_idx: u16) ' +
'-> bool {', '}'):
# The matches emitted by `emit_instp` need this.
fmt.line('use ir::instructions::InstructionFormat;')
with fmt.indented('match instp_idx {', '}'):
for instp in instps:
with fmt.indented('{} => {{'.format(instp.number), '}'):
name = 'inst_predicate_{}'.format(instp.number)
with fmt.indented(
'fn {}(inst: &InstructionData) -> bool {{'
.format(name),
'}'):
emit_instp(instp, fmt)
fmt.line('_ => panic!("Invalid instruction predicate")')
fmt.line('unreachable!();')
# The match cases will fall through if the instruction format is wrong.
fmt.line('panic!("Bad format {:?}/{} for instp {}",')
fmt.line(' InstructionFormat::from(inst),')
fmt.line(' inst.opcode(),')
fmt.line(' instp_idx);')
# Generate the static table.
with fmt.indented(
'pub static INST_PREDICATES: [InstPredicate; {}] = ['
.format(len(instps)), '];'):
for instp in instps:
fmt.format('inst_predicate_{},', instp.number)
def emit_recipe_predicates(recipes, fmt):
@@ -658,8 +649,8 @@ def gen_isa(isa, fmt):
# Make the `RECIPE_PREDICATES` table.
emit_recipe_predicates(isa.all_recipes, fmt)
# Generate the check_instp() function..
emit_instps(isa.all_instps, fmt)
# Make the `INST_PREDICATES` table.
emit_inst_predicates(isa.all_instps, fmt)
# Level1 tables, one per CPU mode
level1_tables = dict()

1
lib/cretonne/src/isa/arm32/enc_tables.rs
View File

@@ -1,6 +1,5 @@
//! Encoding tables for ARM32 ISA.
use ir::InstructionData;
use ir::types;
use isa::EncInfo;
use isa::constraints::*;

2
lib/cretonne/src/isa/arm32/mod.rs
View File

@@ -74,8 +74,8 @@ impl TargetIsa for Isa {
Ok(Encodings::new(enclist_offset,
&enc_tables::ENCLISTS[..],
&enc_tables::RECIPE_PREDICATES[..],
&enc_tables::INST_PREDICATES[..],
inst,
enc_tables::check_instp,
self.isa_flags.predicate_view()))
})
}

1
lib/cretonne/src/isa/arm64/enc_tables.rs
View File

@@ -1,6 +1,5 @@
//! Encoding tables for ARM64 ISA.
use ir::InstructionData;
use ir::types;
use isa::EncInfo;
use isa::constraints::*;

2
lib/cretonne/src/isa/arm64/mod.rs
View File

@@ -67,8 +67,8 @@ impl TargetIsa for Isa {
Ok(Encodings::new(enclist_offset,
&enc_tables::ENCLISTS[..],
&enc_tables::RECIPE_PREDICATES[..],
&enc_tables::INST_PREDICATES[..],
inst,
enc_tables::check_instp,
self.isa_flags.predicate_view()))
})
}

18
lib/cretonne/src/isa/enc_tables.rs
View File

@@ -16,6 +16,12 @@ use std::ops::Range;
/// A None predicate is always satisfied.
pub type RecipePredicate = Option<fn(PredicateView, &InstructionData) -> bool>;
/// An instruction predicate.
///
/// This is a predicate function that needs to be tested in addition to the recipe predicate. It
/// can't depend on ISA settings.
pub type InstPredicate = fn(&InstructionData) -> bool;
/// Legalization action to perform when no encoding can be found for an instruction.
///
/// This is an index into an ISA-specific table of legalization actions.
@@ -152,9 +158,9 @@ pub struct Encodings<'a> {
offset: usize,
enclist: &'static [EncListEntry],
inst: &'a InstructionData,
instp: fn(&InstructionData, EncListEntry) -> bool,
isa_predicates: PredicateView<'a>,
recipe_predicates: &'static [RecipePredicate],
inst_predicates: &'static [InstPredicate],
}
impl<'a> Encodings<'a> {
@@ -176,17 +182,17 @@ impl<'a> Encodings<'a> {
pub fn new(offset: usize,
enclist: &'static [EncListEntry],
recipe_predicates: &'static [RecipePredicate],
inst_predicates: &'static [InstPredicate],
inst: &'a InstructionData,
instp: fn(&InstructionData, EncListEntry) -> bool,
isa_predicates: PredicateView<'a>)
-> Self {
Encodings {
offset,
enclist,
inst,
instp,
isa_predicates,
recipe_predicates,
inst_predicates,
}
}
@@ -208,7 +214,11 @@ impl<'a> Iterator for Encodings<'a> {
if pred <= CODE_ALWAYS {
// This is an instruction predicate followed by recipe and encbits entries.
self.offset += 3;
if pred == CODE_ALWAYS || (self.instp)(self.inst, pred) {
let satisfied = match self.inst_predicates.get(pred as usize) {
Some(p) => p(self.inst),
None => true,
};
if satisfied {
let recipe = self.enclist[self.offset - 2];
if self.check_recipe(recipe) {
let encoding = Encoding::new(recipe, self.enclist[self.offset - 1]);

2
lib/cretonne/src/isa/intel/mod.rs
View File

@@ -74,8 +74,8 @@ impl TargetIsa for Isa {
Ok(Encodings::new(enclist_offset,
&enc_tables::ENCLISTS[..],
&enc_tables::RECIPE_PREDICATES[..],
&enc_tables::INST_PREDICATES[..],
inst,
enc_tables::check_instp,
self.isa_flags.predicate_view()))
})
}

2
lib/cretonne/src/isa/riscv/mod.rs
View File

@@ -74,8 +74,8 @@ impl TargetIsa for Isa {
Ok(Encodings::new(enclist_offset,
&enc_tables::ENCLISTS[..],
&enc_tables::RECIPE_PREDICATES[..],
&enc_tables::INST_PREDICATES[..],
inst,
enc_tables::check_instp,
self.isa_flags.predicate_view()))
})
}