* doc/md.texi (shift patterns): New anchor. Add reference to

	TARGET_SHIFT_TRUNCATION_MASK.
	* doc/tm.texi (TARGET_SHIFT_TRUNCATION_MASK): Document.
	* target.h (shift_truncation_mask): New target hook.
	* targhook.h (default_shift_truncation_mask): Declare.
	* targhook.c (default_shift_truncation_mask): Define.
	* target-def.h (TARGET_SHIFT_TRUNCATION_MASK): Define.
	(TARGET_INITIALIZER): Include it.
	* simplify-rtx.c (simplify_binary_operation): Combine ASHIFT, ASHIFTRT
	and LSHIFTRT cases.  Truncate arg1 if SHIFT_COUNT_TRUNCATED, otherwise
	reject all out-of-range values.  Fix sign-extension code for modes
	whose width is smaller than HOST_BITS_PER_WIDE_INT.
	* optabs.c (simplify_expand_binop, force_expand_binop): New functions.
	(expand_superword_shift, expand_subword_shift): Likewise.
	(expand_doubleword_shift_condmove, expand_doubleword_shift): Likewise.
	(expand_binop): Use them to implement double-word shifts.
	* config/arm/arm.c (arm_shift_truncation_mask): New function.
	(TARGET_SHIFT_TRUNCATION_MASK): Define.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@87079 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 4 insertions, 0 deletions

diff --git a/gcc/target.h b/gcc/target.h
index 035aeed4426..735a85d11dd 100644
--- a/gcc/target.h
+++ b/gcc/target.h
@@ -378,6 +378,10 @@ struct gcc_target
   /* Undo the effects of encode_section_info on the symbol string.  */
   const char * (* strip_name_encoding) (const char *);
 
+  /* If shift optabs for MODE are known to always truncate the shift count,
+     return the mask that they apply.  Return 0 otherwise.  */
+  unsigned HOST_WIDE_INT (* shift_truncation_mask) (enum machine_mode mode);
+
   /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))).  */
   bool (* valid_pointer_mode) (enum machine_mode mode);