From 97f47195c9e677e3c0fb73a0aab9183a98ebb08b Mon Sep 17 00:00:00 2001 From: Taylor R Campbell Date: Thu, 19 Aug 2010 02:55:13 +0000 Subject: [PATCH] Eliminate losing bisection crock in find_block_address. This wasted several hours of my day in exchange for several milliseconds of time (`on average') searching through the heap after a trap that will trigger an interactive debugger anyway and sit waiting for I/O. --- src/microcode/uxtrap.c | 31 +++---------------------------- 1 file changed, 3 insertions(+), 28 deletions(-) diff --git a/src/microcode/uxtrap.c b/src/microcode/uxtrap.c index e139389ae..3121cd0ad 100644 --- a/src/microcode/uxtrap.c +++ b/src/microcode/uxtrap.c @@ -108,8 +108,6 @@ static void continue_from_trap static SCHEME_OBJECT * find_constant_address (unsigned long); # ifdef ENABLE_TRAP_RECOVERY static SCHEME_OBJECT * find_block_address (unsigned long, SCHEME_OBJECT *); - static SCHEME_OBJECT * find_block_address_in_area - (SCHEME_OBJECT *, SCHEME_OBJECT *); # endif #endif @@ -438,15 +436,10 @@ continue_from_trap (int signo, SIGINFO_T info, SIGCONTEXT_T * scp) setup_trap_frame (signo, info, scp, (&recovery_info), new_sp); } -/* Find the compiled code block in area that contains `pc'. - This attempts to be more efficient than `find_block_address_in_area'. - If the pointer is in the heap, it can actually do twice as - much work, but it is expected to pay off on the average. */ +/* Find the compiled code block in area that contains `pc'. */ #ifdef CC_SUPPORT_P -#define MINIMUM_SCAN_RANGE 2048 - static SCHEME_OBJECT * find_heap_address (unsigned long pc) { @@ -459,32 +452,14 @@ find_constant_address (unsigned long pc) return (find_block_address (pc, constant_start)); } -static SCHEME_OBJECT * -find_block_address (unsigned long pc, SCHEME_OBJECT * area_start) -{ - SCHEME_OBJECT * pcp = ((SCHEME_OBJECT *) (pc &~ SCHEME_ALIGNMENT_MASK)); - unsigned long maximum_distance = (pcp - area_start); - unsigned long distance = maximum_distance; - - while ((distance / 2) > MINIMUM_SCAN_RANGE) - distance = (distance / 2); - while (1) - { - SCHEME_OBJECT * block - = (find_block_address_in_area (pcp, (pcp - distance))); - distance *= 2; - if ((block != 0) || (distance >= maximum_distance)) - return (block); - } -} - /* Find the compiled code block in area that contains `pc_value', by scanning sequentially the complete area. For the time being, skip over manifest closures and linkage sections. */ static SCHEME_OBJECT * -find_block_address_in_area (SCHEME_OBJECT * pcp, SCHEME_OBJECT * area_start) +find_block_address (unsigned long pc, SCHEME_OBJECT * area_start) { + SCHEME_OBJECT * pcp = ((SCHEME_OBJECT *) (pc &~ SCHEME_ALIGNMENT_MASK)); SCHEME_OBJECT * first_valid = area_start; SCHEME_OBJECT * area = area_start; -- 2.25.1