On Friday 20 May 2016 14:22:48 Kyrill Tkachov wrote:
> Hi Thomas,
> 

> 
> Hmm, I'm not a fan of this change. arm_print_operand_punct_valid_p is an
> implementation of a target hook that is used to validate user-provided
> inline asm as well and is therefore the right place to reject such invalid
> constructs.
> 
> This is just working around the fact that the output template for the
> [u]divsi3 patterns has a '%?' in it that is illegal in Thumb1 and will not
> be used for ARMv8-M Baseline anyway. I'd prefer it if you add a second
> alternative to those patterns and emit the sdiv/udiv mnemonic without the
> '%?' and enable that for the v8mb arch attribute (and mark the existing
> alternative as requiring the "32" arch attribute).

Fixed.

> 
> s/TARGET_HAVE_MOVT/TARGET_HAVE_CBZ/

Likewise.

> > +  [(set (attr "far_jump")
> > +	(if_then_else
> > +	    (eq_attr "length" "8")
> > +	    (const_string "yes")
> > +	    (const_string "no")))
> > +   (set (attr "length")
> > +	(if_then_else
> > +	    (and (ge (minus (match_dup 2) (pc)) (const_int 2))
> > +		 (le (minus (match_dup 2) (pc)) (const_int 128))
> > +		 (not (match_test "which_alternative")))
> 
> This pattern only has one alternative so "which_alternative"
> will always be 0, so the (not (match_test "which_alternative"))
> test inside the 'and' is redundant and can be removed.

Ditto.

Please find updated ChangeLog entries:

*** gcc/ChangeLog ***

2016-05-23  Thomas Preud'homme  <thomas.preudhomme@arm.com>

        * config/arm/arm.h (TARGET_HAVE_CBZ): Define.
        (TARGET_IDIV): Set for all Thumb targets provided they have hardware
        divide feature.
        * config/arm/arm.md (divsi3): New unpredicable alternative for ARMv8-M
        Baseline.  Make initial alternative TARGET_32BIT only.
        (udivsi3): Likewise.
        * config/arm/thumb1.md (thumb1_cbz): New insn.
        * doc/sourcebuild.texi (arm_thumb1_cbz_ok): Document new effective
        target.


*** gcc/testsuite/ChangeLog ***

2016-05-23  Thomas Preud'homme  <thomas.preudhomme@arm.com>

        * lib/target-supports.exp (check_effective_target_arm_thumb1_cbz_ok):
        Add new arm_thumb1_cbz_ok effective target.
        * gcc.target/arm/cbz.c: New test.


Updated patch in attachment.

Best regards,

Thomas