From: Carsten Haitzler (Rasterman) <raster@rasterman.com>
Date: Sat, 17 Oct 2015 02:42:46 +0000 (+0900)
Subject: eo - another 1.5 percent speedup in eo_bench eo_do by removing err handl
X-Git-Tag: v1.16.0-beta2~8
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=94ebd96df509c36a8d0d12b3e5c9befbf0287441;p=platform%2Fupstream%2Fefl.git

eo - another 1.5 percent speedup in eo_bench eo_do by removing err handl

so we do a bit of error handling like does a stack fail to allocate,
does setting the tls var fail, have the stack frames been nulled or
not allocated, etc. - these acutally cost every call because they mean
some extra compare and branches, but ore because they cause a lot fo
extra code to be generated, thus polluting instruction cache with code
and cacheline fetches of code that we rarely take - if ever.

every if () and DBG, ERR etc. does cost something. in really hotpath
code like this, i think it's best we realize that these checks will
basically never be triggered, because if a stack fails to grow... we
likely alreayd blew our REAL stack for the C/C++ side and that can't
allocate anymore and has already just crashed (no magic message there -
just segv). so in this case i think this checking is pointless and
just costs us rather than gets us anything.
---

diff --git a/src/lib/eo/eo.c b/src/lib/eo/eo.c
index 27073f6..34713f3 100644
--- a/src/lib/eo/eo.c
+++ b/src/lib/eo/eo.c
@@ -389,18 +389,7 @@ _eo_call_stack_get_thread(void)
    if (stack) return stack;
 
    stack = _eo_call_stack_create();
-   if (!stack)
-     {
-        EINA_LOG_ERR("Could not alloc eo call stack.");
-        return NULL;
-     }
-
-   if (!eina_tls_set(_eo_call_stack_key, stack))
-     {
-        EINA_LOG_ERR("Could not set eo call stack in TLS key.");
-        _eo_call_stack_free(stack);
-        return NULL;
-     }
+   eina_tls_set(_eo_call_stack_key, stack);
 
    return stack;
 }
@@ -424,15 +413,9 @@ _eo_call_stack_resize(Eo_Call_Stack *stack, Eina_Bool grow)
      next_sz = sz / 2;
    frame_offset = stack->frame_ptr - stack->frames;
 
-   DBG("resize from %lu to %lu", (long unsigned int)sz, (long unsigned int)next_sz);
    _eo_call_stack_mem_resize((void **)&(stack->frames),
                              next_sz * sizeof(Eo_Stack_Frame),
                              sz * sizeof(Eo_Stack_Frame));
-   if (!stack->frames)
-     {
-        CRI("unable to resize call stack, abort.");
-        abort();
-     }
 
    stack->frame_ptr = &stack->frames[frame_offset];
    stack->last_frame = &stack->frames[next_sz - 1];
@@ -535,12 +518,6 @@ _eo_do_end(void *eo_stack)
 
    fptr->obj_data = EO_INVALID_DATA;
 
-   if (fptr == stack->frames)
-     {
-        CRI("eo call stack underflow, abort.");
-        abort();
-     }
-
    stack->frame_ptr--;
 
    if (fptr == stack->shrink_frame)