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runtime: enable more address bits on macOS/ARM64

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Apparently macOS/ARM64 has 47-bit addresses, instead of 33-bit as
on ios/ARM64. Enable more address bits.

Updates #38485.

Change-Id: I8aa64ba22a3933e3d9c4fffd17d902b5f31c30e3
Reviewed-on: https://go-review.googlesource.com/c/go/+/256918
Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
This commit is contained in:
Cherry Zhang 2020-09-17 10:53:10 -04:00
parent 28e549dec3
commit a739306ca7
3 changed files with 8 additions and 8 deletions
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8
src/runtime/malloc.go
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@ -198,7 +198,7 @@ const (
// mips32 only has access to the low 2GB of virtual memory, so
// we further limit it to 31 bits.
//
// On darwin/arm64, although 64-bit pointers are presumably
// On ios/arm64, although 64-bit pointers are presumably
// available, pointers are truncated to 33 bits. Furthermore,
// only the top 4 GiB of the address space are actually available
// to the application, but we allow the whole 33 bits anyway for
@ -207,7 +207,7 @@ const (
// arenaBaseOffset to offset into the top 4 GiB.
//
// WebAssembly currently has a limit of 4GB linear memory.
heapAddrBits = (_64bit*(1-sys.GoarchWasm)*(1-(sys.GoosDarwin+sys.GoosIos)*sys.GoarchArm64))*48 + (1-_64bit+sys.GoarchWasm)*(32-(sys.GoarchMips+sys.GoarchMipsle)) + 33*(sys.GoosDarwin+sys.GoosIos)*sys.GoarchArm64
heapAddrBits = (_64bit*(1-sys.GoarchWasm)*(1-sys.GoosIos*sys.GoarchArm64))*48 + (1-_64bit+sys.GoarchWasm)*(32-(sys.GoarchMips+sys.GoarchMipsle)) + 33*sys.GoosIos*sys.GoarchArm64
// maxAlloc is the maximum size of an allocation. On 64-bit,
// it's theoretically possible to allocate 1<<heapAddrBits bytes. On
@ -514,14 +514,14 @@ func mallocinit() {
// However, on arm64, we ignore all this advice above and slam the
// allocation at 0x40 << 32 because when using 4k pages with 3-level
// translation buffers, the user address space is limited to 39 bits
// On darwin/arm64, the address space is even smaller.
// On ios/arm64, the address space is even smaller.
//
// On AIX, mmaps starts at 0x0A00000000000000 for 64-bit.
// processes.
for i := 0x7f; i >= 0; i-- {
var p uintptr
switch {
case GOARCH == "arm64" && (GOOS == "darwin" || GOOS == "ios"):
case GOARCH == "arm64" && GOOS == "ios":
p = uintptr(i)<<40 | uintptrMask&(0x0013<<28)
case GOARCH == "arm64":
p = uintptr(i)<<40 | uintptrMask&(0x0040<<32)