diff options
Diffstat (limited to 'src/runtime/alg.go')
| -rw-r--r-- | src/runtime/alg.go | 33 |
1 files changed, 23 insertions, 10 deletions
diff --git a/src/runtime/alg.go b/src/runtime/alg.go index b956f9d05a..c5951dc20b 100644 --- a/src/runtime/alg.go +++ b/src/runtime/alg.go @@ -14,10 +14,23 @@ import ( ) const ( - c0 = uintptr((8-goarch.PtrSize)/4*2860486313 + (goarch.PtrSize-4)/4*33054211828000289) - c1 = uintptr((8-goarch.PtrSize)/4*3267000013 + (goarch.PtrSize-4)/4*23344194077549503) + // We use 32-bit hash on Wasm, see hash32.go. + hashSize = (1-goarch.IsWasm)*goarch.PtrSize + goarch.IsWasm*4 + c0 = uintptr((8-hashSize)/4*2860486313 + (hashSize-4)/4*33054211828000289) + c1 = uintptr((8-hashSize)/4*3267000013 + (hashSize-4)/4*23344194077549503) ) +func trimHash(h uintptr) uintptr { + if goarch.IsWasm != 0 { + // On Wasm, we use 32-bit hash, despite that uintptr is 64-bit. + // memhash* always returns a uintptr with high 32-bit being 0 + // (see hash32.go). We trim the hash in other places where we + // compute the hash manually, e.g. in interhash. + return uintptr(uint32(h)) + } + return h +} + func memhash0(p unsafe.Pointer, h uintptr) uintptr { return h } @@ -100,9 +113,9 @@ func f32hash(p unsafe.Pointer, h uintptr) uintptr { f := *(*float32)(p) switch { case f == 0: - return c1 * (c0 ^ h) // +0, -0 + return trimHash(c1 * (c0 ^ h)) // +0, -0 case f != f: - return c1 * (c0 ^ h ^ uintptr(rand())) // any kind of NaN + return trimHash(c1 * (c0 ^ h ^ uintptr(rand()))) // any kind of NaN default: return memhash(p, h, 4) } @@ -112,9 +125,9 @@ func f64hash(p unsafe.Pointer, h uintptr) uintptr { f := *(*float64)(p) switch { case f == 0: - return c1 * (c0 ^ h) // +0, -0 + return trimHash(c1 * (c0 ^ h)) // +0, -0 case f != f: - return c1 * (c0 ^ h ^ uintptr(rand())) // any kind of NaN + return trimHash(c1 * (c0 ^ h ^ uintptr(rand()))) // any kind of NaN default: return memhash(p, h, 8) } @@ -145,9 +158,9 @@ func interhash(p unsafe.Pointer, h uintptr) uintptr { panic(errorString("hash of unhashable type " + toRType(t).string())) } if t.IsDirectIface() { - return c1 * typehash(t, unsafe.Pointer(&a.data), h^c0) + return trimHash(c1 * typehash(t, unsafe.Pointer(&a.data), h^c0)) } else { - return c1 * typehash(t, a.data, h^c0) + return trimHash(c1 * typehash(t, a.data, h^c0)) } } @@ -172,9 +185,9 @@ func nilinterhash(p unsafe.Pointer, h uintptr) uintptr { panic(errorString("hash of unhashable type " + toRType(t).string())) } if t.IsDirectIface() { - return c1 * typehash(t, unsafe.Pointer(&a.data), h^c0) + return trimHash(c1 * typehash(t, unsafe.Pointer(&a.data), h^c0)) } else { - return c1 * typehash(t, a.data, h^c0) + return trimHash(c1 * typehash(t, a.data, h^c0)) } } |