Re: [Patch, avr] Fix PR 67839 - bit addressable instructions generated for out of range addresses

[Senthil Kumar Selvaraj <senthil_kumar dot selvaraj at atmel dot com>]

Ping!

Regards
Senthil
On Fri, Oct 16, 2015 at 03:17:17PM +0530, Senthil Kumar Selvaraj wrote:
> Ping!
> 
> Regards
> Senthil
> 
> On Mon, Oct 05, 2015 at 02:30:58PM +0530, Senthil Kumar Selvaraj wrote:
> > Hi,
> > 
> >   As part of support for io and io_low attributes, the upper bound of
> >   the range check for low IO and IO addresses was changed from hardcoded
> >   values to hardcoded_range_end + 1 - GET_MODE_SIZE(mode).
> > 
> >   GCC passes VOID as the mode from genrecog, and GET_MODE_SIZE returns
> >   0, resulting in the range getting incorrectly extended by a byte.
> > 
> >   Not sure why it was done, as the mode of the operand shouldn't really
> >   matter when computing the upper bound. In any case, the insns that use 
> > 	the predicate already have a mem:QI wrapping it, and all the bit
> >   addressable instructions operate on a single IO register only.
> > 
> >   This patch reverts the check back to a hardcoded value, and adds a
> >   test to prevent regressions.
> > 
> >   No new regression failures. If ok, could someone commit please? I
> > 	don't have commit access.
> > 
> > 
> > Regards
> > Senthil
> > 
> > gcc/ChangeLog
> > 
> > 2015-10-05  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
> > 
> > 	PR target/67839
> > 	* config/avr/predicates.md (low_io_address_operand): Don't
> > 	consider MODE when computing upper bound.
> > 	(io_address_operand): Likewise.
> > 
> > 
> > gcc/testsuite/ChangeLog
> > 
> > 2015-10-05  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
> > 
> > 	PR target/67839
> > 	* gcc.target/avr/pr67839.c: New test.
> > 
> > 
> > 
> > diff --git gcc/config/avr/predicates.md gcc/config/avr/predicates.md
> > index 2d12bc6..622bc0b 100644
> > --- gcc/config/avr/predicates.md
> > +++ gcc/config/avr/predicates.md
> > @@ -46,7 +46,7 @@
> >  (define_special_predicate "low_io_address_operand"
> >    (ior (and (match_code "const_int")
> >  	    (match_test "IN_RANGE (INTVAL (op) - avr_arch->sfr_offset,
> > -				   0, 0x20 - GET_MODE_SIZE (mode))"))
> > +				   0, 0x1F)"))
> >         (and (match_code "symbol_ref")
> >  	    (match_test "SYMBOL_REF_FLAGS (op) & SYMBOL_FLAG_IO_LOW"))))
> >  
> > @@ -60,7 +60,7 @@
> >  (define_special_predicate "io_address_operand"
> >    (ior (and (match_code "const_int")
> >  	    (match_test "IN_RANGE (INTVAL (op) - avr_arch->sfr_offset,
> > -				   0, 0x40 - GET_MODE_SIZE (mode))"))
> > +				   0, 0x3F)"))
> >         (and (match_code "symbol_ref")
> >  	    (match_test "SYMBOL_REF_FLAGS (op) & SYMBOL_FLAG_IO"))))
> >  
> > diff --git gcc/testsuite/gcc.target/avr/pr67839.c gcc/testsuite/gcc.target/avr/pr67839.c
> > new file mode 100644
> > index 0000000..604ab4b
> > --- /dev/null
> > +++ gcc/testsuite/gcc.target/avr/pr67839.c
> > @@ -0,0 +1,29 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-Os" } */
> > +/* { dg-final { scan-assembler "sbi 0x1f,0" } } */
> > +/* { dg-final { scan-assembler "cbi 0x1f,0" } } */
> > +/* { dg-final { scan-assembler-not "sbi 0x20,0" } } */
> > +/* { dg-final { scan-assembler-not "cbi 0x20,0" } } */
> > +/* { dg-final { scan-assembler "in r\\d+,__SREG__" } } */
> > +/* { dg-final { scan-assembler "out __SREG__,r\\d+" } } */
> > +/* { dg-final { scan-assembler-not "in r\\d+,0x40" } } */
> > +/* { dg-final { scan-assembler-not "out 0x40, r\\d+" } } */
> > +
> > +/* This testcase verifies that SBI/CBI/SBIS/SBIC
> > +   and IN/OUT instructions are not generated for
> > +   an IO addresses outside the valid range.
> > +*/
> > +#define IO_ADDR(x) (*((volatile char *)x + __AVR_SFR_OFFSET__))
> > +int main ()
> > +{
> > +  IO_ADDR(0x1f) |= 1;
> > +  IO_ADDR(0x1f) &= 0xFE;
> > +
> > +  IO_ADDR(0x20) |= 1;
> > +  IO_ADDR(0x20) &= 0xFE;
> > +
> > +  IO_ADDR(0x3f) = IO_ADDR(0x3f);
> > +
> > +  IO_ADDR(0x40) = IO_ADDR(0x40);
> > +  return 0;
> > +}