Re: Q.: inconsistent (?) warnings about functions called through non-compatible types

2015-03-29 Thread Godmar Back
On Sun, Mar 29, 2015 at 3:26 PM, Andreas Schwab wrote: > Godmar Back writes: > >> ps: I would like to see the warning, of course, since casting a bool >> returning function to an int returning function is undefined behavior. > > The cast itself is ok, the undefined b

Q.: inconsistent (?) warnings about functions called through non-compatible types

2015-03-29 Thread Godmar Back
Hi, why does gcc (4.4.7 and 4.8.2) sometimes warn and sometimes not warn when undefined behavior is invoked when making illegal function pointer conversions? For instance, consider the code below: - /* Tested with gcc 4.4.7 and 4.8.2 */ #include #include bool boolFunctionThatReturnsFa

Re: rationale for eliding modifications to string constants

2010-09-14 Thread Godmar Back
On Tue, Sep 14, 2010 at 2:35 PM, Ian Lance Taylor wrote: > > I think this is simply a bug.  It doesn't happen with current gcc.  With > gcc 4.4.3 the assignment is being eliminated because it is considered to > be dead code. > > I agree that it is an error for gcc to simply eliminate this assignme

rationale for eliding modifications to string constants

2010-09-14 Thread Godmar Back
Hi, this may be a FAQ - in my class today when discussing how gcc generates code for x86, I was stumped when I showed an example of how gcc handles attempts to modify (read-only) string literals/constants. (I'm sending this to gcc rather than gcc-help because I'm asking for a design rationale - I

Re: question about -mpush-args -maccumulate-outgoing-args on gcc for x86

2009-09-01 Thread Godmar Back
On Tue, Sep 1, 2009 at 12:31 PM, Ian Lance Taylor wrote: > Godmar Back writes: > >> It appears to me that '-mno-push-args' is the enabled by default (*), >> and not '-mpush-args'. > > The default varies by processor--it dependson the -mtune option.

Re: question about -mpush-args -maccumulate-outgoing-args on gcc for x86

2009-09-01 Thread Godmar Back
Minor correction to my previous email: On Tue, Sep 1, 2009 at 10:08 AM, Godmar Back wrote: > > gb...@setzer [39](~/tmp) > cat call.c > void caller(void) { >    extern void callee(int); >    callee(5); > } This: > gb...@setzer [40](~/tmp) > gcc -mno-push-args -S cal

question about -mpush-args -maccumulate-outgoing-args on gcc for x86

2009-09-01 Thread Godmar Back
Hi, I'm using gcc version 4.1.2 20080704 (Red Hat 4.1.2-44) for a x86 target. The info page says: `-mpush-args' `-mno-push-args' Use PUSH operations to store outgoing parameters. This method is shorter and usually equally fast as method using SUB/MOV operations and is enabled by d