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fix: polyfills for small types in builtin_rotl/rotr should use temp variables #1505

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Merged
merged 1 commit into from
Oct 15, 2020
Merged

fix: polyfills for small types in builtin_rotl/rotr should use temp variables #1505

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56 changes: 46 additions & 10 deletions src/builtins.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -1177,22 +1177,40 @@ function builtin_rotl(ctx: BuiltinContext): ExpressionRef {
case TypeKind.U8:
case TypeKind.U16: {
// (value << (shift & mask)) | (value >>> ((0 - shift) & mask))
return module.binary(BinaryOp.OrI32,
let flow = compiler.currentFlow;
let temp1 = flow.getTempLocal(type);
flow.setLocalFlag(temp1.index, LocalFlags.WRAPPED);
let temp2 = flow.getTempLocal(type);
flow.setLocalFlag(temp2.index, LocalFlags.WRAPPED);

let ret = module.binary(BinaryOp.OrI32,
module.binary(
BinaryOp.ShlI32,
arg0,
module.binary(BinaryOp.AndI32, arg1, module.i32(type.size - 1))
module.local_tee(temp1.index, arg0),
module.binary(
BinaryOp.AndI32,
module.local_tee(temp2.index, arg1),
module.i32(type.size - 1)
)
),
module.binary(
BinaryOp.ShrU32,
arg0,
module.local_get(temp1.index, NativeType.I32),
module.binary(
BinaryOp.AndI32,
module.binary(BinaryOp.SubI32, module.i32(0), arg1),
module.binary(
BinaryOp.SubI32,
module.i32(0),
module.local_get(temp2.index, NativeType.I32)
),
module.i32(type.size - 1)
)
)
);
flow.freeTempLocal(temp2);
flow.freeTempLocal(temp1);

return ret;
}
case TypeKind.I32:
case TypeKind.U32: return module.binary(BinaryOp.RotlI32, arg0, arg1);
Expand Down Expand Up @@ -1240,22 +1258,40 @@ function builtin_rotr(ctx: BuiltinContext): ExpressionRef {
case TypeKind.U8:
case TypeKind.U16: {
// (value >>> (shift & mask)) | (value << ((0 - shift) & mask))
return module.binary(BinaryOp.OrI32,
let flow = compiler.currentFlow;
let temp1 = flow.getTempLocal(type);
flow.setLocalFlag(temp1.index, LocalFlags.WRAPPED);
let temp2 = flow.getTempLocal(type);
flow.setLocalFlag(temp2.index, LocalFlags.WRAPPED);

let ret = module.binary(BinaryOp.OrI32,
module.binary(
BinaryOp.ShrU32,
arg0,
module.binary(BinaryOp.AndI32, arg1, module.i32(type.size - 1))
module.local_tee(temp1.index, arg0),
module.binary(
BinaryOp.AndI32,
module.local_tee(temp2.index, arg1),
module.i32(type.size - 1)
)
),
module.binary(
BinaryOp.ShlI32,
arg0,
module.local_get(temp1.index, NativeType.I32),
module.binary(
BinaryOp.AndI32,
module.binary(BinaryOp.SubI32, module.i32(0), arg1),
module.binary(
BinaryOp.SubI32,
module.i32(0),
module.local_get(temp2.index, NativeType.I32)
),
module.i32(type.size - 1)
)
)
);
flow.freeTempLocal(temp2);
flow.freeTempLocal(temp1);

return ret;
}
case TypeKind.I32:
case TypeKind.U32: return module.binary(BinaryOp.RotrI32, arg0, arg1);
Expand Down
12 changes: 8 additions & 4 deletions tests/compiler/builtins.untouched.wat
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Original file line number Diff line number Diff line change
Expand Up @@ -502,13 +502,15 @@
unreachable
end
i32.const 143
local.tee $0
i32.const 3
local.tee $1
i32.const 7
i32.and
i32.shl
i32.const 143
local.get $0
i32.const 0
i32.const 3
local.get $1
i32.sub
i32.const 7
i32.and
Expand All @@ -530,13 +532,15 @@
unreachable
end
i32.const 170
local.tee $0
i32.const 1
local.tee $1
i32.const 7
i32.and
i32.shr_u
i32.const 170
local.get $0
i32.const 0
i32.const 1
local.get $1
i32.sub
i32.const 7
i32.and
Expand Down