Source code
Revision control
Copy as Markdown
Other Tools
// The result should be -1 because it is (i32.rem_s -1 10000) and the spec
// stipulates "result has the sign of the dividend". This test uncovers a bug
// in SpiderMonkey wherein the shape of the lhs (it looks like an unsigned
// value) causes an unsigned modulo to be emitted.
assertEq(wasmEvalText(
`(module
(func (result i32)
(i32.const -1)
(i32.const 0)
i32.shr_u
(i32.const 10000)
i32.rem_s)
(export "f" (func 0)))`).exports.f(), -1);
// Ditto for int64
wasmAssert(
`(module
(func $run (result i64)
(i64.const -1)
(i64.const 0)
i64.shr_u
(i64.const 10000)
i64.rem_s)
)`, [{type:'i64', expected:'0xffffffffffffffff', func:'$run'}]);
// Despite the signed shift this is 0x80000000 % 10000 (rem_u)
// and the result is positive.
assertEq(wasmEvalText(
`(module
(func (result i32)
(i32.const -1)
(i32.const 0)
i32.shl
(i32.const 10000)
i32.rem_u)
(export "f" (func 0)))`).exports.f(), 7295);
// 0x80000000 is really -0x80000000 so the result of signed division shall be
// negative.
assertEq(wasmEvalText(
`(module
(func (result i32)
(i32.const 0x80000000)
(i32.const 0)
i32.shr_u
(i32.const 10000)
i32.div_s)
(export "f" (func 0)))`).exports.f(), -214748);
assertEq(wasmEvalText(
`(module
(func (result i32)
(i32.const 0x80000000)
(i32.const 0)
i32.shr_u
(i32.const -10000)
i32.div_s)
(export "f" (func 0)))`).exports.f(), 214748);
// And the result of unsigned division shall be positive.
assertEq(wasmEvalText(
`(module
(func (result i32)
(i32.const 0x80000000)
(i32.const 0)
i32.shr_u
(i32.const 10000)
i32.div_u)
(export "f" (func 0)))`).exports.f(), 214748);