[RFC] Context sensitive inline analysis

[Richard Sandiford]

Richard Sandiford <richard.sandiford@linaro.org> writes:
> Jan Hubicka <hubicka@ucw.cz> writes:
>> the problem is sign overflow in time computation. Time should be
>> capped by MAX_TIME and we compute MAX_TIME * INLINE_SIZE_SCALE *
>> 2. This happens to be >2^31 & <2^32 so we overflow here because of use
>> of signed arithmetics.
>>
>> Index: ipa-inline-analysis.c
>> ===================================================================
>> --- ipa-inline-analysis.c	(revision 179266)
>> +++ ipa-inline-analysis.c	(working copy)
>> @@ -92,7 +92,7 @@ along with GCC; see the file COPYING3.
>>  /* Estimate runtime of function can easilly run into huge numbers with many
>>     nested loops.  Be sure we can compute time * INLINE_SIZE_SCALE in integer.
>>     For anything larger we use gcov_type.  */
>> -#define MAX_TIME 1000000
>> +#define MAX_TIME 500000
>>  
>>  /* Number of bits in integer, but we really want to be stable across different
>>     hosts.  */
>
> Could you update the comment too?  ("time * INLINE_SIZE_SCALE * 2")

OK, I did it myself.  Tested on x86_64-linux-gnu and applied as obvious.

Richard


gcc/
	* ipa-inline-analysis.c (MAX_TIME): Update comment.

Index: gcc/ipa-inline-analysis.c
===================================================================
--- gcc/ipa-inline-analysis.c	2011-10-03 09:10:21.000000000 +0100
+++ gcc/ipa-inline-analysis.c	2011-10-03 09:10:55.633044417 +0100
@@ -90,8 +90,8 @@ Software Foundation; either version 3, o
 #include "alloc-pool.h"
 
 /* Estimate runtime of function can easilly run into huge numbers with many
-   nested loops.  Be sure we can compute time * INLINE_SIZE_SCALE in integer.
-   For anything larger we use gcov_type.  */
+   nested loops.  Be sure we can compute time * INLINE_SIZE_SCALE * 2 in an
+   integer.  For anything larger we use gcov_type.  */
 #define MAX_TIME 500000
 
 /* Number of bits in integer, but we really want to be stable across different