diff options
Diffstat (limited to 'src/pkg/runtime/malloc.go')
| -rw-r--r-- | src/pkg/runtime/malloc.go | 88 |
1 files changed, 39 insertions, 49 deletions
diff --git a/src/pkg/runtime/malloc.go b/src/pkg/runtime/malloc.go index 84c69abde7..152b3b6b68 100644 --- a/src/pkg/runtime/malloc.go +++ b/src/pkg/runtime/malloc.go @@ -225,66 +225,56 @@ func gomallocgc(size uintptr, typ *_type, flags int) unsafe.Pointer { *xbits |= (bitsPointer << 2) << shift goto marked } - if typ != nil && (uintptr(typ.gc[0])|uintptr(typ.gc[1])) != 0 && uintptr(typ.size) > ptrSize { - if typ.kind&kindGCProg != 0 { - nptr := (uintptr(typ.size) + ptrSize - 1) / ptrSize - masksize := nptr - if masksize%2 != 0 { - masksize *= 2 // repeated - } - masksize = masksize * pointersPerByte / 8 // 4 bits per word - masksize++ // unroll flag in the beginning - if masksize > maxGCMask && typ.gc[1] != 0 { - // If the mask is too large, unroll the program directly - // into the GC bitmap. It's 7 times slower than copying - // from the pre-unrolled mask, but saves 1/16 of type size - // memory for the mask. - mp := acquirem() - mp.ptrarg[0] = x - mp.ptrarg[1] = unsafe.Pointer(typ) - mp.scalararg[0] = uint(size) - mp.scalararg[1] = uint(size0) - onM(&unrollgcproginplace_m) - releasem(mp) - goto marked - } - ptrmask = (*uint8)(unsafe.Pointer(uintptr(typ.gc[0]))) - // Check whether the program is already unrolled. - if uintptr(goatomicloadp(unsafe.Pointer(ptrmask)))&0xff == 0 { - mp := acquirem() - mp.ptrarg[0] = unsafe.Pointer(typ) - onM(&unrollgcprog_m) - releasem(mp) - } - ptrmask = (*uint8)(add(unsafe.Pointer(ptrmask), 1)) // skip the unroll flag byte - } else { - ptrmask = (*uint8)(unsafe.Pointer(&typ.gc[0])) // embed mask + if typ.kind&kindGCProg != 0 { + nptr := (uintptr(typ.size) + ptrSize - 1) / ptrSize + masksize := nptr + if masksize%2 != 0 { + masksize *= 2 // repeated } - if size == 2*ptrSize { - xbitsb := (*uint8)(add(unsafe.Pointer(xbits), shift/8)) - *xbitsb = *ptrmask | bitBoundary + masksize = masksize * pointersPerByte / 8 // 4 bits per word + masksize++ // unroll flag in the beginning + if masksize > maxGCMask && typ.gc[1] != 0 { + // If the mask is too large, unroll the program directly + // into the GC bitmap. It's 7 times slower than copying + // from the pre-unrolled mask, but saves 1/16 of type size + // memory for the mask. + mp := acquirem() + mp.ptrarg[0] = x + mp.ptrarg[1] = unsafe.Pointer(typ) + mp.scalararg[0] = uint(size) + mp.scalararg[1] = uint(size0) + onM(&unrollgcproginplace_m) + releasem(mp) goto marked } - te = uintptr(typ.size) / ptrSize - // If the type occupies odd number of words, its mask is repeated. - if te%2 == 0 { - te /= 2 + ptrmask = (*uint8)(unsafe.Pointer(uintptr(typ.gc[0]))) + // Check whether the program is already unrolled. + if uintptr(goatomicloadp(unsafe.Pointer(ptrmask)))&0xff == 0 { + mp := acquirem() + mp.ptrarg[0] = unsafe.Pointer(typ) + onM(&unrollgcprog_m) + releasem(mp) } + ptrmask = (*uint8)(add(unsafe.Pointer(ptrmask), 1)) // skip the unroll flag byte + } else { + ptrmask = (*uint8)(unsafe.Pointer(&typ.gc[0])) // embed mask } if size == 2*ptrSize { xbitsb := (*uint8)(add(unsafe.Pointer(xbits), shift/8)) - *xbitsb = (bitsPointer << 2) | (bitsPointer << 6) | bitBoundary + *xbitsb = *ptrmask | bitBoundary goto marked } + te = uintptr(typ.size) / ptrSize + // If the type occupies odd number of words, its mask is repeated. + if te%2 == 0 { + te /= 2 + } // Copy pointer bitmask into the bitmap. for i := uintptr(0); i < size0; i += 2 * ptrSize { - v := uint8((bitsPointer << 2) | (bitsPointer << 6)) - if ptrmask != nil { - v = *(*uint8)(add(unsafe.Pointer(ptrmask), ti)) - ti++ - if ti == te { - ti = 0 - } + v := *(*uint8)(add(unsafe.Pointer(ptrmask), ti)) + ti++ + if ti == te { + ti = 0 } if i == 0 { v |= bitBoundary |