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Fix some 16- and 8-bit behavior in x64 backend related to rotates.

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Uncovered by @bjorn3 (thanks!): 8- and 16-bit rotates were not working
properly in recent versions of Cranelift with part of the lowering
migrated to ISLE.

This PR fixes a few issues:

- 8- and 16-bit rotate-left needs to mask a constant amount, if any,
  because we use a 32-bit rotate instruction and so don't get the
  appropriate shift-amount masking for free from x86 semantics.

- `operand_size_from_type` was incorrect: it only handled 32- and 64-bit
  types and silently returned `OperandSize::Size32` for everything else.
  Now uses the `OperandSize::from_ty(ty)` helper as the pre-ISLE code
  did.

Our test coverage for narrow value types is not great; this PR adds some
runtests for rotl/rotr but more would always be better!
This commit is contained in:
Chris Fallin
2021-12-16 11:34:24 -08:00
parent d29b7c8a59
commit 1323ae417e
10 changed files with 352 additions and 229 deletions
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13
cranelift/codegen/src/isa/aarch64/lower/isle/generated_code.rs generated
View File

@@ -34,6 +34,8 @@ pub trait Context {
fn ty_bits_u16(&mut self, arg0: Type) -> u16;
fn fits_in_32(&mut self, arg0: Type) -> Option<Type>;
fn fits_in_64(&mut self, arg0: Type) -> Option<Type>;
fn ty_32_or_64(&mut self, arg0: Type) -> Option<Type>;
fn ty_8_or_16(&mut self, arg0: Type) -> Option<Type>;
fn vec128(&mut self, arg0: Type) -> Option<Type>;
fn not_i64x2(&mut self, arg0: Type) -> Option<()>;
fn value_list_slice(&mut self, arg0: ValueList) -> ValueSlice;
@@ -49,6 +51,7 @@ pub trait Context {
fn first_result(&mut self, arg0: Inst) -> Option<Value>;
fn inst_data(&mut self, arg0: Inst) -> InstructionData;
fn value_type(&mut self, arg0: Value) -> Type;
fn ty_bits_mask(&mut self, arg0: Type) -> u64;
fn multi_lane(&mut self, arg0: Type) -> Option<(u8, u16)>;
fn def_inst(&mut self, arg0: Value) -> Option<Inst>;
fn trap_code_division_by_zero(&mut self) -> TrapCode;
@@ -79,13 +82,13 @@ pub trait Context {
fn safe_divisor_from_imm64(&mut self, arg0: Imm64) -> Option<u64>;
}
/// Internal type ProducesFlags: defined at src/prelude.isle line 246.
/// Internal type ProducesFlags: defined at src/prelude.isle line 259.
#[derive(Clone, Debug)]
pub enum ProducesFlags {
ProducesFlags { inst: MInst, result: Reg },
}
/// Internal type ConsumesFlags: defined at src/prelude.isle line 249.
/// Internal type ConsumesFlags: defined at src/prelude.isle line 262.
#[derive(Clone, Debug)]
pub enum ConsumesFlags {
ConsumesFlags { inst: MInst, result: Reg },
@@ -999,7 +1002,7 @@ pub fn constructor_with_flags<C: Context>(
result: pattern3_1,
} = pattern2_0
{
// Rule at src/prelude.isle line 259.
// Rule at src/prelude.isle line 272.
let expr0_0 = C::emit(ctx, &pattern1_0);
let expr1_0 = C::emit(ctx, &pattern3_0);
let expr2_0 = C::value_regs(ctx, pattern1_1, pattern3_1);
@@ -1027,7 +1030,7 @@ pub fn constructor_with_flags_1<C: Context>(
result: pattern3_1,
} = pattern2_0
{
// Rule at src/prelude.isle line 267.
// Rule at src/prelude.isle line 280.
let expr0_0 = C::emit(ctx, &pattern1_0);
let expr1_0 = C::emit(ctx, &pattern3_0);
return Some(pattern3_1);
@@ -1061,7 +1064,7 @@ pub fn constructor_with_flags_2<C: Context>(
result: pattern5_1,
} = pattern4_0
{
// Rule at src/prelude.isle line 277.
// Rule at src/prelude.isle line 290.
let expr0_0 = C::emit(ctx, &pattern1_0);
let expr1_0 = C::emit(ctx, &pattern3_0);
let expr2_0 = C::emit(ctx, &pattern5_0);