rs6000-protos.h (expand_strn_compare): Declare.

	* config/rs6000/rs6000-protos.h (expand_strn_compare): Declare.
	* config/rs6000/rs6000.md (UNSPEC_CMPB): New unspec.
	(cmpb<mode>3): pattern for generating cmpb.
	(cmpstrnsi): pattern to expand strncmp ().
	* config/rs6000/rs6000.opt (mstring-compare-inline-limit): Add a new
	target option for controlling how much code inline expansion of
	strncmp() will be allowed to generate.
	* config/rs6000/rs6000.c (expand_strncmp_align_check): generate code
	for runtime page crossing check of strncmp () args.
	(expand_strn_compare): Function to do builtin expansion of strncmp ().

From-SVN: r243813

gcc/ChangeLog

+2016-12-19  Aaron Sawdey  <acsawdey@linux.vnet.ibm.com>
+
+	* config/rs6000/rs6000-protos.h (expand_strn_compare): Declare.
+	* config/rs6000/rs6000.md (UNSPEC_CMPB): New unspec.
+	(cmpb<mode>3): pattern for generating cmpb.
+	(cmpstrnsi): pattern to expand strncmp ().
+	* config/rs6000/rs6000.opt (mstring-compare-inline-limit): Add a new
+	target option for controlling how much code inline expansion of
+	strncmp() will be allowed to generate.
+	* config/rs6000/rs6000.c (expand_strncmp_align_check): generate code
+	for runtime page crossing check of strncmp () args.
+	(expand_strn_compare): Function to do builtin expansion of strncmp ().
+
 2016-12-19  David Malcolm  <dmalcolm@redhat.com>
 
 	* print-rtl-function.c (print_rtx_function): Update

gcc/config/rs6000/rs6000-protos.h

@@ -78,6 +78,7 @@ extern void rs6000_scale_v2df (rtx, rtx, int);
 extern int expand_block_clear (rtx[]);
 extern int expand_block_move (rtx[]);
 extern bool expand_block_compare (rtx[]);
+extern bool expand_strn_compare (rtx[]);
 extern const char * rs6000_output_load_multiple (rtx[]);
 extern bool rs6000_is_valid_mask (rtx, int *, int *, machine_mode);
 extern bool rs6000_is_valid_and_mask (rtx, machine_mode);

gcc/config/rs6000/rs6000.md

@@ -117,6 +117,7 @@
    UNSPEC_BPERM
    UNSPEC_COPYSIGN
    UNSPEC_PARITY
+   UNSPEC_CMPB
    UNSPEC_FCTIW
    UNSPEC_FCTID
    UNSPEC_LFIWAX
@@ -2316,6 +2317,13 @@
   "prty<wd> %0,%1"
   [(set_attr "type" "popcnt")])
 
+(define_insn "cmpb<mode>3"
+  [(set (match_operand:GPR 0 "gpc_reg_operand" "=r")
+	(unspec:GPR [(match_operand:GPR 1 "gpc_reg_operand" "r")
+		     (match_operand:GPR 2 "gpc_reg_operand" "r")] UNSPEC_CMPB))]
+  "TARGET_CMPB"
+  "cmpb %0,%1,%2"
+  [(set_attr "type" "cmp")])
 
 ;; Since the hardware zeros the upper part of the register, save generating the
 ;; AND immediate if we are converting to unsigned
@@ -8844,7 +8852,28 @@
     FAIL;
 }")
 
-;; String/block compare insn.
+;; String compare N insn.
+;; Argument 0 is the target (result)
+;; Argument 1 is the destination
+;; Argument 2 is the source
+;; Argument 3 is the length
+;; Argument 4 is the alignment
+
+(define_expand "cmpstrnsi"
+  [(parallel [(set (match_operand:SI 0)
+               (compare:SI (match_operand:BLK 1)
+                           (match_operand:BLK 2)))
+	      (use (match_operand:SI 3))
+	      (use (match_operand:SI 4))])]
+  "TARGET_CMPB && (BYTES_BIG_ENDIAN || TARGET_LDBRX)"
+{
+  if (expand_strn_compare (operands))
+    DONE;
+  else	
+    FAIL;
+})
+
+;; Block compare insn.
 ;; Argument 0 is the target (result)
 ;; Argument 1 is the destination
 ;; Argument 2 is the source

gcc/config/rs6000/rs6000.opt

@@ -337,6 +337,10 @@ mblock-compare-inline-limit=
 Target Report Var(rs6000_block_compare_inline_limit) Init(5) RejectNegative Joined UInteger Save
 Specify the maximum number pairs of load instructions that should be generated inline for the compare.  If the number needed exceeds the limit, a call to memcmp will be generated instead.
 
+mstring-compare-inline-limit=
+Target Report Var(rs6000_string_compare_inline_limit) Init(8) RejectNegative Joined UInteger Save
+Specify the maximum number pairs of load instructions that should be generated inline for the compare.  If the number needed exceeds the limit, a call to strncmp will be generated instead.
+
 misel
 Target Report Mask(ISEL) Var(rs6000_isa_flags)
 Generate isel instructions.