diff options
| -rw-r--r-- | js/src/jit/arm64/Architecture-arm64.h | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/js/src/jit/arm64/Architecture-arm64.h b/js/src/jit/arm64/Architecture-arm64.h index e74340f13..bee212db7 100644 --- a/js/src/jit/arm64/Architecture-arm64.h +++ b/js/src/jit/arm64/Architecture-arm64.h @@ -299,10 +299,12 @@ static const uint32_t ION_FRAME_SLACK_SIZE = 24; static const uint32_t ShadowStackSpace = 0; -// TODO: -// This constant needs to be updated to account for whatever near/far branching -// strategy is used by ARM64. -static const uint32_t JumpImmediateRange = UINT32_MAX; +// When our only strategy for far jumps is to encode the offset directly, and +// not insert any jump islands during assembly for even further jumps, then the +// architecture restricts us to -2^27 .. 2^27-4, to fit into a signed 28-bit +// value. We further reduce this range to allow the far-jump inserting code to +// have some breathing room. +static const uint32_t JumpImmediateRange = ((1 << 27) - (20 * 1024 * 1024)); static const uint32_t ABIStackAlignment = 16; static const uint32_t CodeAlignment = 16; |