wasmcurves
Version:
elliptic curves implementations in wasm
81 lines (70 loc) • 2.65 kB
JavaScript
module.exports = buildBatchConvertion;
function buildBatchConvertion(module, fnName, internalFnName, sizeIn, sizeOut, reverse) {
if (typeof reverse === "undefined") {
// Set the reverse in a way that allows to use the same buffer as in/out.
if (sizeIn < sizeOut) {
reverse = true;
} else {
reverse = false;
}
}
const f = module.addFunction(fnName);
f.addParam("pIn", "i32");
f.addParam("n", "i32");
f.addParam("pOut", "i32");
f.addLocal("i", "i32");
f.addLocal("itIn", "i32");
f.addLocal("itOut", "i32");
const c = f.getCodeBuilder();
if (reverse) {
f.addCode(
c.setLocal("itIn",
c.i32_add(
c.getLocal("pIn"),
c.i32_mul(
c.i32_sub(
c.getLocal("n"),
c.i32_const(1)
),
c.i32_const(sizeIn)
)
)
),
c.setLocal("itOut",
c.i32_add(
c.getLocal("pOut"),
c.i32_mul(
c.i32_sub(
c.getLocal("n"),
c.i32_const(1)
),
c.i32_const(sizeOut)
)
)
),
c.setLocal("i", c.i32_const(0)),
c.block(c.loop(
c.br_if(1, c.i32_eq ( c.getLocal("i"), c.getLocal("n") )),
c.call(internalFnName, c.getLocal("itIn"), c.getLocal("itOut")),
c.setLocal("itIn", c.i32_sub(c.getLocal("itIn"), c.i32_const(sizeIn))),
c.setLocal("itOut", c.i32_sub(c.getLocal("itOut"), c.i32_const(sizeOut))),
c.setLocal("i", c.i32_add(c.getLocal("i"), c.i32_const(1))),
c.br(0)
)),
);
} else {
f.addCode(
c.setLocal("itIn", c.getLocal("pIn")),
c.setLocal("itOut", c.getLocal("pOut")),
c.setLocal("i", c.i32_const(0)),
c.block(c.loop(
c.br_if(1, c.i32_eq ( c.getLocal("i"), c.getLocal("n") )),
c.call(internalFnName, c.getLocal("itIn"), c.getLocal("itOut")),
c.setLocal("itIn", c.i32_add(c.getLocal("itIn"), c.i32_const(sizeIn))),
c.setLocal("itOut", c.i32_add(c.getLocal("itOut"), c.i32_const(sizeOut))),
c.setLocal("i", c.i32_add(c.getLocal("i"), c.i32_const(1))),
c.br(0)
)),
);
}
}