diff options
Diffstat (limited to 'wasm2c/wasm-rt.h')
| -rw-r--r-- | wasm2c/wasm-rt.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/wasm2c/wasm-rt.h b/wasm2c/wasm-rt.h index c489c850..b72d12df 100644 --- a/wasm2c/wasm-rt.h +++ b/wasm2c/wasm-rt.h @@ -217,6 +217,18 @@ extern "C" { #endif /** + * The segue optimization restores x86 segments to their old values when exiting + * wasm2c code. If WASM_RT_SEGUE_FREE_SEGMENT is defined, wasm2c assumes it has + * exclusive use of the segment and optimizes performance in two ways. First, it + * does not restore the "old" value of the segment during exits. Second, wasm2c + * only sets the segment register if the value has changed since the last time + * it was set. + */ +#ifndef WASM_RT_SEGUE_FREE_SEGMENT +#define WASM_RT_SEGUE_FREE_SEGMENT 0 +#endif + +/** * This macro, if defined, allows the embedder to disable all stack exhaustion * checks. This a non conformant configuration, i.e., this does not respect * Wasm's specification, and may compromise security. Use with caution. @@ -313,6 +325,14 @@ void wasm_rt_syscall_set_segue_base(void* base); * a function that invokes the OS' underlying syscall to get the segment base. */ void* wasm_rt_syscall_get_segue_base(); +/** + * If WASM_RT_SEGUE_FREE_SEGMENT is defined, we must only set the segment + * register if it was changed since the last time it was set. The last value set + * on the segment register is stored in this variable. + */ +#if WASM_RT_SEGUE_FREE_SEGMENT +extern WASM_RT_THREAD_LOCAL void* wasm_rt_last_segment_val; +#endif #endif #if defined(_MSC_VER) |