T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Remove SSE2 setting for x86

Browse Source 
In talking to @sunfishcode, he preferred to avoid the confusion of more ISA predicates by eliminating SSE2. SSE2 was released with the Pentium 4 in 2000 so it is unlikely that current CPUs would have SIMD enabled and not have this feature. I tried to note the SSE2-specific instructions with comments in the code.
This commit is contained in:
Andrew Brown
2019-07-17 09:45:58 -07:00
committed by Dan Gohman
parent 6605f308b3
commit b4ef90cfcd
5 changed files with 53 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files

71
cranelift/codegen/meta/src/isa/x86/encodings.rs
View File

@@ -268,14 +268,38 @@ impl PerCpuModeEncodings {
}
/// Add the same encoding to both X86_32 and X86_64; assumes configuration (e.g. REX, operand binding) has already happened
fn enc_32_64_isap(
fn enc_32_64_maybe_isap(
&mut self,
inst: BoundInstruction,
template: Template,
isap: SettingPredicateNumber,
isap: Option<SettingPredicateNumber>,
) {
self.enc32_isap(inst.clone(), template.clone(), isap);
self.enc64_isap(inst, template, isap);
self.enc32_maybe_isap(inst.clone(), template.clone(), isap);
self.enc64_maybe_isap(inst, template, isap);
}
fn enc32_maybe_isap(
&mut self,
inst: BoundInstruction,
template: Template,
isap: Option<SettingPredicateNumber>,
) {
match isap {
None => self.enc32(inst, template),
Some(isap) => self.enc32_isap(inst, template, isap),
}
}
fn enc64_maybe_isap(
&mut self,
inst: BoundInstruction,
template: Template,
isap: Option<SettingPredicateNumber>,
) {
match isap {
None => self.enc64(inst, template),
Some(isap) => self.enc64_isap(inst, template, isap),
}
}
}
@@ -559,7 +583,6 @@ pub fn define(
let use_popcnt = settings.predicate_by_name("use_popcnt");
let use_lzcnt = settings.predicate_by_name("use_lzcnt");
let use_bmi1 = settings.predicate_by_name("use_bmi1");
let use_sse2 = settings.predicate_by_name("use_sse2");
let use_ssse3 = settings.predicate_by_name("use_ssse3");
let use_sse41 = settings.predicate_by_name("use_sse41");
@@ -1648,8 +1671,8 @@ pub fn define(
let template = rec_r_ib_unsigned_fpr
.nonrex()
.opcodes(vec![0x66, 0x0f, 0x70]);
e.enc32_isap(instruction.clone(), template.clone(), use_sse2);
e.enc64_isap(instruction, template, use_sse2);
e.enc32(instruction.clone(), template.clone());
e.enc64(instruction, template);
}
// SIMD scalar_to_vector; this uses MOV to copy the scalar value to an XMM register; according
@@ -1662,47 +1685,49 @@ pub fn define(
let template = rec_frurm.opcodes(vec![0x66, 0x0f, 0x6e]); // MOVD/MOVQ
if ty.lane_bits() < 64 {
// no 32-bit encodings for 64-bit widths
e.enc32_isap(instruction.clone(), template.clone(), use_sse2);
e.enc32(instruction.clone(), template.clone());
}
e.enc_x86_64_isap(instruction, template, use_sse2);
e.enc_x86_64(instruction, template);
}
// SIMD insertlane
let mut insertlane_mapping: HashMap<u64, (Vec<u8>, SettingPredicateNumber)> = HashMap::new();
insertlane_mapping.insert(8, (vec![0x66, 0x0f, 0x3a, 0x20], use_sse41)); // PINSRB
insertlane_mapping.insert(16, (vec![0x66, 0x0f, 0xc4], use_sse2)); // PINSRW
insertlane_mapping.insert(32, (vec![0x66, 0x0f, 0x3a, 0x22], use_sse41)); // PINSRD
insertlane_mapping.insert(64, (vec![0x66, 0x0f, 0x3a, 0x22], use_sse41)); // PINSRQ, only x86_64
let mut insertlane_mapping: HashMap<u64, (Vec<u8>, Option<SettingPredicateNumber>)> =
HashMap::new();
insertlane_mapping.insert(8, (vec![0x66, 0x0f, 0x3a, 0x20], Some(use_sse41))); // PINSRB
insertlane_mapping.insert(16, (vec![0x66, 0x0f, 0xc4], None)); // PINSRW from SSE2
insertlane_mapping.insert(32, (vec![0x66, 0x0f, 0x3a, 0x22], Some(use_sse41))); // PINSRD
insertlane_mapping.insert(64, (vec![0x66, 0x0f, 0x3a, 0x22], Some(use_sse41))); // PINSRQ, only x86_64
for ty in ValueType::all_lane_types() {
if let Some((opcode, isap)) = insertlane_mapping.get(&ty.lane_bits()) {
let instruction = insertlane.bind_vector_from_lane(ty, sse_vector_size);
let template = rec_r_ib_unsigned_r.opcodes(opcode.clone());
if ty.lane_bits() < 64 {
e.enc_32_64_isap(instruction, template.nonrex(), isap.clone());
e.enc_32_64_maybe_isap(instruction, template.nonrex(), isap.clone());
} else {
// turns out the 64-bit widths have REX/W encodings and only are available on x86_64
e.enc64_isap(instruction, template.rex().w(), isap.clone());
e.enc64_maybe_isap(instruction, template.rex().w(), isap.clone());
}
}
}
// SIMD extractlane
let mut extractlane_mapping: HashMap<u64, (Vec<u8>, SettingPredicateNumber)> = HashMap::new();
extractlane_mapping.insert(8, (vec![0x66, 0x0f, 0x3a, 0x14], use_sse41)); // PEXTRB
extractlane_mapping.insert(16, (vec![0x66, 0x0f, 0xc5], use_sse2)); // PEXTRW, SSE4.1 has a PEXTRW that can move to reg/m16 but the opcode is four bytes
extractlane_mapping.insert(32, (vec![0x66, 0x0f, 0x3a, 0x16], use_sse41)); // PEXTRD
extractlane_mapping.insert(64, (vec![0x66, 0x0f, 0x3a, 0x16], use_sse41)); // PEXTRQ, only x86_64
let mut extractlane_mapping: HashMap<u64, (Vec<u8>, Option<SettingPredicateNumber>)> =
HashMap::new();
extractlane_mapping.insert(8, (vec![0x66, 0x0f, 0x3a, 0x14], Some(use_sse41))); // PEXTRB
extractlane_mapping.insert(16, (vec![0x66, 0x0f, 0xc5], None)); // PEXTRW from zSSE2, SSE4.1 has a PEXTRW that can move to reg/m16 but the opcode is four bytes
extractlane_mapping.insert(32, (vec![0x66, 0x0f, 0x3a, 0x16], Some(use_sse41))); // PEXTRD
extractlane_mapping.insert(64, (vec![0x66, 0x0f, 0x3a, 0x16], Some(use_sse41))); // PEXTRQ, only x86_64
for ty in ValueType::all_lane_types() {
if let Some((opcode, isap)) = extractlane_mapping.get(&ty.lane_bits()) {
let instruction = extractlane.bind_vector_from_lane(ty, sse_vector_size);
let template = rec_r_ib_unsigned_gpr.opcodes(opcode.clone());
if ty.lane_bits() < 64 {
e.enc_32_64_isap(instruction, template.nonrex(), isap.clone());
e.enc_32_64_maybe_isap(instruction, template.nonrex(), isap.clone());
} else {
// turns out the 64-bit widths have REX/W encodings and only are available on x86_64
e.enc64_isap(instruction, template.rex().w(), isap.clone());
e.enc64_maybe_isap(instruction, template.rex().w(), isap.clone());
}
}
}

9
cranelift/codegen/meta/src/isa/x86/settings.rs
View File

@@ -3,9 +3,6 @@ use crate::cdsl::settings::{PredicateNode, SettingGroup, SettingGroupBuilder};
pub fn define(shared: &SettingGroup) -> SettingGroup {
let mut settings = SettingGroupBuilder::new("x86");
// CPUID.01H:EDX
let has_sse2 = settings.add_bool("has_sse2", "SSE2: CPUID.01H:EDX.SSE2[bit 26]", false);
// CPUID.01H:ECX
let has_sse3 = settings.add_bool("has_sse3", "SSE3: CPUID.01H:ECX.SSE3[bit 0]", false);
let has_ssse3 = settings.add_bool("has_ssse3", "SSSE3: CPUID.01H:ECX.SSSE3[bit 9]", false);
@@ -35,7 +32,6 @@ pub fn define(shared: &SettingGroup) -> SettingGroup {
let shared_enable_simd = shared.get_bool("enable_simd");
settings.add_predicate("use_sse2", predicate!(shared_enable_simd && has_sse2));
settings.add_predicate("use_ssse3", predicate!(shared_enable_simd && has_ssse3));
settings.add_predicate("use_sse41", predicate!(shared_enable_simd && has_sse41));
settings.add_predicate(
@@ -69,7 +65,7 @@ pub fn define(shared: &SettingGroup) -> SettingGroup {
settings.add_preset("baseline", preset!());
let nehalem = settings.add_preset(
"nehalem",
preset!(has_sse2 && has_sse3 && has_ssse3 && has_sse41 && has_sse42 && has_popcnt),
preset!(has_sse3 && has_ssse3 && has_sse41 && has_sse42 && has_popcnt),
);
let haswell = settings.add_preset(
"haswell",
@@ -82,8 +78,7 @@ pub fn define(shared: &SettingGroup) -> SettingGroup {
settings.add_preset(
"znver1",
preset!(
has_sse2
&& has_sse3
has_sse3
&& has_ssse3
&& has_sse41
&& has_sse42