u256 wide multiplication

[Genya-Z]

Adding u256_wide_mul and u128_to_64s.

---

This change is 

[dorimedini-starkware]

Reviewed 3 of 6 files at r2.
Reviewable status: 3 of 8 files reviewed, 4 unresolved discussions (waiting on @Genya-Z)

---

corelib/test.cairo line 713 at r2 (raw file):

    assert(
	high == as_u256(130366876754661164843311819125622077435_u128,
			238310065584501807926300814868835410406_u128),

what are these numbers? used named variables please

Code quote:

    let(low,high)=integer::u256_wide_mul(as_u256(155419417030398358529415680970430503750_u128,
						 208595563450721923828867081157420252200_u128),
					 as_u256(285431191531813133557775306831253175872_u128,
						 43439607001498238463885217561246358334_u128));
    assert(
        low == as_u256(74008176751363765864810996693396202398_u128,
		       113989470359884732637183370837798242736_u128),
	'wide mul low'
    );
    assert(
	high == as_u256(130366876754661164843311819125622077435_u128,
			238310065584501807926300814868835410406_u128),
        'wide mul high'
    );

---

crates/cairo-lang-sierra/src/extensions/modules/uint128.rs line 166 at r2 (raw file):

        context: &dyn SignatureSpecializationContext,
    ) -> Result<LibfuncSignature, SpecializationError> {
        let ty = context.get_concrete_type(Uint128Type::id(), &[])?;

rename

Suggestion:

        let ty_u128 = context.get_concrete_type(Uint128Type::id(), &[])?;
        let ty_u64 = context.get_concrete_type(Uint64Type::id(), &[])?;

---

crates/cairo-lang-sierra-to-casm/src/invocations/uint128.rs line 218 at r2 (raw file):

    Ok(builder.build_from_casm_builder(
        casm_builder,
        [("Fallthrough", &[&[range_check], &[low], &[high]], None)],

why this order?

Code quote:

&[low], &[high]

---

docs/CODE_OF_CONDUCT.md line 1 at r2 (raw file):

# Contributor Covenant Code of Conduct

why is this deleted?

[dorimedini-starkware]

Reviewable status: 2 of 8 files reviewed, 5 unresolved discussions (waiting on @Genya-Z)

---

corelib/integer.cairo line 770 at r2 (raw file):

const HALF_SHIFT : felt = 18446744073709551616;//2^64;
//const HALF_SHIFTb  = u128_as_non_zero(18446744073709551616_u128);//2^64;
fn u256_wide_mul(a: u256, b: u256) -> (u256, u256) implicits(RangeCheck) {

deleted commented code lines throughout this function

[dorimedini-starkware]

Reviewed 1 of 1 files at r4.
Reviewable status: 3 of 8 files reviewed, 4 unresolved discussions (waiting on @Genya-Z)

[dorimedini-starkware]

Reviewed all commit messages.
Reviewable status: 3 of 8 files reviewed, 4 unresolved discussions (waiting on @Genya-Z)

[Genya-Z]

Reviewable status: 3 of 8 files reviewed, 4 unresolved discussions (waiting on @dorimedini-starkware)

---

corelib/test.cairo line 713 at r2 (raw file):

Previously, dorimedini-starkware wrote…

what are these numbers? used named variables please

These are random integers I generated to test the multiplication routine.

---

crates/cairo-lang-sierra/src/extensions/modules/uint128.rs line 166 at r2 (raw file):

Previously, dorimedini-starkware wrote…

rename

Done.

---

crates/cairo-lang-sierra-to-casm/src/invocations/uint128.rs line 218 at r2 (raw file):

Previously, dorimedini-starkware wrote…

why this order?

It's how the function worked in the Cairo 0 version.

[dorimedini-starkware]

Reviewed all commit messages.
Reviewable status: 3 of 8 files reviewed, 3 unresolved discussions (waiting on @Genya-Z and @orizi)

---

corelib/test.cairo line 713 at r2 (raw file):

Previously, Genya-Z wrote…

These are random integers I generated to test the multiplication routine.

please add some edge cases with named constants

---

crates/cairo-lang-sierra-to-casm/src/invocations/uint128.rs line 218 at r2 (raw file):

Previously, Genya-Z wrote…

It's how the function worked in the Cairo 0 version.

@orizi WDYT?

[dorimedini-starkware]

Reviewed 3 of 8 files at r6, all commit messages.
Reviewable status: 4 of 10 files reviewed, 6 unresolved discussions (waiting on @Genya-Z and @orizi)

---

crates/cairo-lang-sierra/src/extensions/modules/uint128.rs line 28 at r6 (raw file):

        Operation(UintOperationLibfunc<Uint128Traits>),
        Divmod(UintDivmodLibfunc<Uint128Traits>),
	Split(Uint128ToUint64sLibfunc),

for spaces instead of tabs (everywhere)

---

corelib/integer.cairo line 0 at r6 (raw file):
why deleted?

---

corelib/test.cairo line 0 at r6 (raw file):
why deleted?

[Genya-Z]

Reviewable status: 4 of 10 files reviewed, 6 unresolved discussions (waiting on @dorimedini-starkware and @orizi)

---

corelib/integer.cairo line 770 at r2 (raw file):

Previously, dorimedini-starkware wrote…

deleted commented code lines throughout this function

Done.

---

corelib/integer.cairo line at r6 (raw file):

Previously, dorimedini-starkware wrote…

why deleted?

It was moved into /src/ in the main branch.

---

corelib/test.cairo line 713 at r2 (raw file):

Previously, dorimedini-starkware wrote…

please add some edge cases with named constants

Done.

[Genya-Z]

Reviewable status: 3 of 10 files reviewed, 6 unresolved discussions (waiting on @dorimedini-starkware and @orizi)

---

crates/cairo-lang-sierra/src/extensions/modules/uint128.rs line 28 at r6 (raw file):

Previously, dorimedini-starkware wrote…

for spaces instead of tabs (everywhere)

Done.

[dorimedini-starkware]

Reviewable status: 3 of 10 files reviewed, 5 unresolved discussions (waiting on @Genya-Z and @orizi)

---

crates/cairo-lang-sierra/src/extensions/modules/uint128.rs line 28 at r6 (raw file):

Previously, Genya-Z wrote…

Done.

nope :)
also, I meant four spaces instead of tabs

[dorimedini-starkware]

Reviewable status: 3 of 10 files reviewed, 5 unresolved discussions (waiting on @Genya-Z and @orizi)

---

crates/cairo-lang-sierra/src/extensions/modules/uint128.rs line 28 at r6 (raw file):

Previously, dorimedini-starkware wrote…

nope :)
also, I meant four spaces instead of tabs

TAL at the formatter errors in the CI

[orizi]

Reviewable status: 3 of 10 files reviewed, 7 unresolved discussions (waiting on @dorimedini-starkware and @Genya-Z)

a discussion (no related file):
please run ./scripts/rust_fmt.sh and `./scripts/cairo_fmt.sh

---

---

crates/cairo-lang-sierra/src/simulation/core.rs line 476 at r3 (raw file):

                        CoreValue::RangeCheck,
                        CoreValue::Uint64((x % 1<<64).try_into().unwrap()),
                        CoreValue::Uint64((x / 1<<64).try_into().unwrap()),

Suggestion:

                        CoreValue::RangeCheck,
                        CoreValue::Uint64((x & u64::MAX).try_into().unwrap()),
                        CoreValue::Uint64((x >> 64).try_into().unwrap()),

[Genya-Z]

Reviewable status: 3 of 10 files reviewed, 7 unresolved discussions (waiting on @dorimedini-starkware and @orizi)

a discussion (no related file):

Previously, orizi wrote…

please run ./scripts/rust_fmt.sh and `./scripts/cairo_fmt.sh

I get

Code snippet:

error: no such command: `+nightly-2022-11-03`

        Cargo does not handle `+toolchain` directives.
        Did you mean to invoke `cargo` through `rustup` instead?

---

---

crates/cairo-lang-sierra/src/extensions/modules/uint128.rs line 28 at r6 (raw file):

Previously, dorimedini-starkware wrote…

TAL at the formatter errors in the CI

Done.

---

crates/cairo-lang-sierra/src/simulation/core.rs line 476 at r3 (raw file):

                        CoreValue::RangeCheck,
                        CoreValue::Uint64((x % 1<<64).try_into().unwrap()),
                        CoreValue::Uint64((x / 1<<64).try_into().unwrap()),

Done.

[orizi]

Reviewable status: 1 of 10 files reviewed, 7 unresolved discussions (waiting on @dorimedini-starkware and @Genya-Z)

a discussion (no related file):

Previously, Genya-Z wrote…

I get

if you'd run these it would conform your code to our formatting, and prevent the relevant ci failures.

---

[orizi]

Reviewable status: 1 of 10 files reviewed, 7 unresolved discussions (waiting on @dorimedini-starkware and @Genya-Z)

---

crates/cairo-lang-sierra-to-casm/src/invocations/uint128.rs line 218 at r2 (raw file):

Previously, dorimedini-starkware wrote…

@orizi WDYT?

it should be in the other order - to match u128s_from_felt - which is the existing split function.

[dorimedini-starkware]

Reviewed 1 of 3 files at r1, 1 of 8 files at r6, 1 of 1 files at r8, 1 of 2 files at r9, 5 of 5 files at r11, all commit messages.
Reviewable status: all files reviewed, 7 unresolved discussions (waiting on @Genya-Z and @orizi)

---

corelib/src/integer.cairo line 766 at r11 (raw file):

const HALF_SHIFT : felt = 18446744073709551616;//2^64;

@Genya-Z any evidence that this is cheaper?
@orizi any suggestions on how to test if it is?

[dorimedini-starkware]

Reviewable status: 3 of 10 files reviewed, 7 unresolved discussions (waiting on @Genya-Z and @orizi)

a discussion (no related file):

Previously, orizi wrote…

if you'd run these it would conform your code to our formatting, and prevent the relevant ci failures.

did you first run rustup override set stable && rustup update && cargo test as mentioned in the README?

---

[dorimedini-starkware]

Reviewed 3 of 5 files at r14, all commit messages.
Reviewable status: 6 of 10 files reviewed, 8 unresolved discussions (waiting on @Genya-Z and @orizi)

---

corelib/src/test.cairo line 694 at r14 (raw file):

    );

    let (low, high) = integer::u256_wide_mul(as_u256(4_u128, 3_u128), as_u256(0_u128, 1_u128));

please add this comnent

Suggestion:

// u256_wide_mul tests.
let (low, high) = integer::u256_wide_mul(as_u256(4_u128, 3_u128), as_u256(0_u128, 1_u128));

---

crates/cairo-lang-sierra/src/extensions/modules/uint128.rs line 197 at r14 (raw file):

                    ref_info: OutputVarReferenceInfo::NewTempVar { idx: Some(0) },
                },
                OutputVarInfo {

@orizi should these be with idx: 1, idx: 2 or 0,1 as it is now?

Code quote:

                OutputVarInfo {
                    ty: ty_u64.clone(),
                    ref_info: OutputVarReferenceInfo::NewTempVar { idx: Some(0) },
                },
                OutputVarInfo {
                    ty: ty_u64,
                    ref_info: OutputVarReferenceInfo::NewTempVar { idx: Some(1) },
                },

[Genya-Z]

Reviewable status: 6 of 10 files reviewed, 7 unresolved discussions (waiting on @dorimedini-starkware and @orizi)

a discussion (no related file):

Previously, dorimedini-starkware wrote…

did you first run rustup override set stable && rustup update && cargo test as mentioned in the README?

Done.

---

---

crates/cairo-lang-sierra-to-casm/src/invocations/uint128.rs line 218 at r2 (raw file):

Previously, orizi wrote…

it should be in the other order - to match u128s_from_felt - which is the existing split function.

Done.

---

docs/CODE_OF_CONDUCT.md line 1 at r2 (raw file):

Previously, dorimedini-starkware wrote…

why is this deleted?

Done.

---

corelib/test.cairo line at r6 (raw file):

Previously, dorimedini-starkware wrote…

why deleted?

File was moved.