* arm.c (arm_legitimate_address_p): New argument, OUTER.  Pass through
to arm_legitimate_index_p.  Update all callers with SET as default
value.
(arm_legitimate_index_p): New argument, OUTER.  Restrict the index
range if OUTER is a sign-extend operation on QImode.  Correctly
reject shift operations on sign-extended QImode addresses.
(bad_signed_byte_operand): Delete.
(arm_extendqisi_mem_op): New function.
* arm.h (EXTRA_CONSTRAINT_ARM): Delete.  Replace with...
(EXTRA_CONSTRAINT_STR_ARM): ... this.  Handle extended address
constraints.
(CONSTRAINT_LEN): New.
(EXTRA_CONSTRAINT): Delete.  Replace with...
(EXTRA_CONSTRAINT_STR): ... this.
(PREDICATE_CODES): Remove bad_signed_byte_operand.
* arm.md (extendqihi_insn): Use new constraint Uq.  Rework.  Length
is now always default.
(define_splits for bad sign-extend loads): Delete.
(arm_extendqisi, arm_extendqisi_v5): Likewise.
* arm/vfp.md (arm_movsi_vfp, arm_movdi_vfp, movsf_vfp, movdf_vfp):
Rework 'U' constraint to 'Uv'.
* arm-protos.h: Remove bad_signed_byte_operand.  Add
arm_extendqisi_mem_op.
* doc/md.texi (ARM constraints): Rename VFP constraint (now Uv).
Add Uq constraint.

From-SVN: r79440