i386.h (TARGET_MISALIGNED_MOVE_STRING_PROLOGUES_EPILOGUES): New tuning flag.

	* i386.h (TARGET_MISALIGNED_MOVE_STRING_PROLOGUES_EPILOGUES): New tuning flag.
	* x86-tune.def (TARGET_MISALIGNED_MOVE_STRING_PROLOGUES): Define it.
	* i386.c (expand_small_movmem_or_setmem): New function.
	(expand_set_or_movmem_prologue_epilogue_by_misaligned_moves): New function
	(alg_usable_p): Add support for value ranges; cleanup.
	(ix86_expand_set_or_movmem): Add support for misaligned moves.

From-SVN: r203937

gcc/ChangeLog

+2013-10-22  Jan Hubicka  <jh@suse.cz>
+
+	* i386.h (TARGET_MISALIGNED_MOVE_STRING_PROLOGUES_EPILOGUES): New tuning flag.
+	* x86-tune.def (TARGET_MISALIGNED_MOVE_STRING_PROLOGUES): Define it.
+	* i386.c (expand_small_movmem_or_setmem): New function.
+	(expand_set_or_movmem_prologue_epilogue_by_misaligned_moves): New function
+	(alg_usable_p): Add support for value ranges; cleanup.
+	(ix86_expand_set_or_movmem): Add support for misaligned moves.
+
 2013-10-22  Sterling Augustine  <saugustine@google.com>
 
 	* doc/invoke.texi: Document -ggnu-pubnames.

gcc/config/i386/i386.h

@@ -350,6 +350,8 @@ extern unsigned char ix86_tune_features[X86_TUNE_LAST];
 #define TARGET_PROMOTE_QImode	ix86_tune_features[X86_TUNE_PROMOTE_QIMODE]
 #define TARGET_FAST_PREFIX	ix86_tune_features[X86_TUNE_FAST_PREFIX]
 #define TARGET_SINGLE_STRINGOP	ix86_tune_features[X86_TUNE_SINGLE_STRINGOP]
+#define TARGET_MISALIGNED_MOVE_STRING_PROLOGUES_EPILOGUES \
+	ix86_tune_features[TARGET_MISALIGNED_MOVE_STRING_PROLOGUES]
 #define TARGET_QIMODE_MATH	ix86_tune_features[X86_TUNE_QIMODE_MATH]
 #define TARGET_HIMODE_MATH	ix86_tune_features[X86_TUNE_HIMODE_MATH]
 #define TARGET_PROMOTE_QI_REGS	ix86_tune_features[X86_TUNE_PROMOTE_QI_REGS]

gcc/config/i386/x86-tune.def

@@ -239,6 +239,15 @@ DEF_TUNE (X86_TUNE_AVOID_MEM_OPND_FOR_CMOVE, "avoid_mem_opnd_for_cmove",
    as MOVS and STOS (without a REP prefix) to move/set sequences of bytes.  */
 DEF_TUNE (X86_TUNE_SINGLE_STRINGOP, "single_stringop", m_386 | m_P4_NOCONA)
 
+/* TARGET_MISALIGNED_MOVE_STRING_PROLOGUES: Enable generation of compace
+   prologues and epilogues by issuing a misaligned moves.  This require
+   target to handle misaligned moves and partial memory stalls resonably
+   well.  
+   FIXME: This actualy may be a win on more targets than listed here.  */
+DEF_TUNE (TARGET_MISALIGNED_MOVE_STRING_PROLOGUES,
+	  "misaligned_move_string_prologues",
+	  m_386 | m_486 | m_CORE_ALL | m_AMD_MULTIPLE | m_GENERIC)
+
 /* X86_TUNE_USE_SAHF: Controls use of SAHF.  */
 DEF_TUNE (X86_TUNE_USE_SAHF, "use_sahf",
           m_PPRO | m_P4_NOCONA | m_CORE_ALL | m_ATOM | m_SLM | m_K6_GEODE