Turn SLOW_UNALIGNED_ACCESS into a target hook

2017-09-12  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood <david.sherwood@arm.com>

gcc/
	* defaults.h (SLOW_UNALIGNED_ACCESS): Delete.
	* target.def (slow_unaligned_access): New hook.
	* targhooks.h (default_slow_unaligned_access): Declare.
	* targhooks.c (default_slow_unaligned_access): New function.
	* doc/tm.texi.in (SLOW_UNALIGNED_ACCESS): Replace with...
	(TARGET_SLOW_UNALIGNED_ACCESS): ...this.
	* doc/tm.texi: Regenerate.
	* config/alpha/alpha.h (SLOW_UNALIGNED_ACCESS): Delete.
	* config/arm/arm.h (SLOW_UNALIGNED_ACCESS): Delete.
	* config/i386/i386.h (SLOW_UNALIGNED_ACCESS): Delete commented-out
	definition.
	* config/powerpcspe/powerpcspe.h (SLOW_UNALIGNED_ACCESS): Delete.
	* config/powerpcspe/powerpcspe.c (TARGET_SLOW_UNALIGNED_ACCESS):
	Redefine.
	(rs6000_slow_unaligned_access): New function.
	(rs6000_emit_move): Use it instead of SLOW_UNALIGNED_ACCESS.
	(expand_block_compare): Likewise.
	(expand_strn_compare): Likewise.
	(rs6000_rtx_costs): Likewise.
	* config/riscv/riscv.h (SLOW_UNALIGNED_ACCESS): Delete.
	(riscv_slow_unaligned_access): Likewise.
	* config/riscv/riscv.c (riscv_slow_unaligned_access): Rename to...
	(riscv_slow_unaligned_access_p): ...this and make static.
	(riscv_option_override): Update accordingly.
	(riscv_slow_unaligned_access): New function.
	(TARGET_SLOW_UNALIGNED_ACCESS): Redefine.
	* config/rs6000/rs6000.h (SLOW_UNALIGNED_ACCESS): Delete.
	* config/rs6000/rs6000.c (TARGET_SLOW_UNALIGNED_ACCESS): Redefine.
	(rs6000_slow_unaligned_access): New function.
	(rs6000_emit_move): Use it instead of SLOW_UNALIGNED_ACCESS.
	(rs6000_rtx_costs): Likewise.
	* config/rs6000/rs6000-string.c (expand_block_compare)
	(expand_strn_compare): Use targetm.slow_unaligned_access instead
	of SLOW_UNALIGNED_ACCESS.
	* config/tilegx/tilegx.h (SLOW_UNALIGNED_ACCESS): Delete.
	* config/tilepro/tilepro.h (SLOW_UNALIGNED_ACCESS): Delete.
	* calls.c (expand_call): Use targetm.slow_unaligned_access instead
	of SLOW_UNALIGNED_ACCESS.
	* expmed.c (simple_mem_bitfield_p): Likewise.
	* expr.c (alignment_for_piecewise_move): Likewise.
	(emit_group_load_1): Likewise.
	(emit_group_store): Likewise.
	(copy_blkmode_from_reg): Likewise.
	(emit_push_insn): Likewise.
	(expand_assignment): Likewise.
	(store_field): Likewise.
	(expand_expr_real_1): Likewise.
	* gimple-fold.c (gimple_fold_builtin_memory_op): Likewise.
	* lra-constraints.c (simplify_operand_subreg): Likewise.
	* stor-layout.c (bit_field_mode_iterator::next_mode): Likewise.
	* gimple-ssa-store-merging.c: Likewise in block comment at start
	of file.
	* tree-ssa-strlen.c: Include target.h.
	(handle_builtin_memcmp): Use targetm.slow_unaligned_access instead
	of SLOW_UNALIGNED_ACCESS.
	* system.h (SLOW_UNALIGNED_ACCESS): Poison.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r252009

3 files changed, 33 insertions, 27 deletions

diff --git a/gcc/config/rs6000/rs6000-string.c b/gcc/config/rs6000/rs6000-string.c
index fb57ab3..19463c9 100644
--- a/gcc/config/rs6000/rs6000-string.c
+++ b/gcc/config/rs6000/rs6000-string.c
@@ -32,6 +32,7 @@
 #include "explow.h"
 #include "expr.h"
 #include "output.h"
+#include "target.h"
 
 /* Expand a block clear operation, and return 1 if successful.  Return 0
    if we should let the compiler generate normal code.
@@ -338,9 +339,9 @@ expand_block_compare (rtx operands[])
 
   unsigned int base_align = UINTVAL (align_rtx) / BITS_PER_UNIT;
 
-  /* SLOW_UNALIGNED_ACCESS -- don't do unaligned stuff.  */
-  if (SLOW_UNALIGNED_ACCESS (word_mode, MEM_ALIGN (orig_src1))
-      || SLOW_UNALIGNED_ACCESS (word_mode, MEM_ALIGN (orig_src2)))
+  /* targetm.slow_unaligned_access -- don't do unaligned stuff.  */
+  if (targetm.slow_unaligned_access (word_mode, MEM_ALIGN (orig_src1))
+      || targetm.slow_unaligned_access (word_mode, MEM_ALIGN (orig_src2)))
     return false;
 
   gcc_assert (GET_MODE (target) == SImode);
@@ -729,9 +730,9 @@ expand_strn_compare (rtx operands[], int no_length)
   int align1 = MEM_ALIGN (orig_src1) / BITS_PER_UNIT;
   int align2 = MEM_ALIGN (orig_src2) / BITS_PER_UNIT;
 
-  /* SLOW_UNALIGNED_ACCESS -- don't do unaligned stuff.  */
-  if (SLOW_UNALIGNED_ACCESS (word_mode, align1)
-      || SLOW_UNALIGNED_ACCESS (word_mode, align2))
+  /* targetm.slow_unaligned_access -- don't do unaligned stuff.  */
+  if (targetm.slow_unaligned_access (word_mode, align1)
+      || targetm.slow_unaligned_access (word_mode, align2))
     return false;
 
   gcc_assert (GET_MODE (target) == SImode);
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index ecdf776..2ff7e1e 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -1976,6 +1976,9 @@ static const struct attribute_spec rs6000_attribute_table[] =
 #undef TARGET_HARD_REGNO_CALL_PART_CLOBBERED
 #define TARGET_HARD_REGNO_CALL_PART_CLOBBERED \
   rs6000_hard_regno_call_part_clobbered
+
+#undef TARGET_SLOW_UNALIGNED_ACCESS
+#define TARGET_SLOW_UNALIGNED_ACCESS rs6000_slow_unaligned_access
 
 
 /* Processor table.  */
@@ -7902,6 +7905,20 @@ rs6000_data_alignment (tree type, unsigned int align, enum data_align how)
   return align;
 }
 
+/* Implement TARGET_SLOW_UNALIGNED_ACCESS.  Altivec vector memory
+   instructions simply ignore the low bits; VSX memory instructions
+   are aligned to 4 or 8 bytes.  */
+
+static bool
+rs6000_slow_unaligned_access (machine_mode mode, unsigned int align)
+{
+  return (STRICT_ALIGNMENT
+	  || (!TARGET_EFFICIENT_UNALIGNED_VSX
+	      && ((SCALAR_FLOAT_MODE_NOT_VECTOR_P (mode) && align < 32)
+		  || ((VECTOR_MODE_P (mode) || FLOAT128_VECTOR_P (mode))
+		      && (int) align < VECTOR_ALIGN (mode)))));
+}
+
 /* Previous GCC releases forced all vector types to have 16-byte alignment.  */
 
 bool
@@ -10500,13 +10517,14 @@ rs6000_emit_move (rtx dest, rtx source, machine_mode mode)
   if (GET_CODE (operands[0]) == MEM
       && GET_CODE (operands[1]) == MEM
       && mode == DImode
-      && (SLOW_UNALIGNED_ACCESS (DImode, MEM_ALIGN (operands[0]))
-	  || SLOW_UNALIGNED_ACCESS (DImode, MEM_ALIGN (operands[1])))
-      && ! (SLOW_UNALIGNED_ACCESS (SImode, (MEM_ALIGN (operands[0]) > 32
-					    ? 32 : MEM_ALIGN (operands[0])))
-	    || SLOW_UNALIGNED_ACCESS (SImode, (MEM_ALIGN (operands[1]) > 32
-					       ? 32
-					       : MEM_ALIGN (operands[1]))))
+      && (rs6000_slow_unaligned_access (DImode, MEM_ALIGN (operands[0]))
+	  || rs6000_slow_unaligned_access (DImode, MEM_ALIGN (operands[1])))
+      && ! (rs6000_slow_unaligned_access (SImode,
+					  (MEM_ALIGN (operands[0]) > 32
+					   ? 32 : MEM_ALIGN (operands[0])))
+	    || rs6000_slow_unaligned_access (SImode,
+					     (MEM_ALIGN (operands[1]) > 32
+					      ? 32 : MEM_ALIGN (operands[1]))))
       && ! MEM_VOLATILE_P (operands [0])
       && ! MEM_VOLATILE_P (operands [1]))
     {
@@ -34252,7 +34270,7 @@ rs6000_rtx_costs (rtx x, machine_mode mode, int outer_code,
 	 than generating address, e.g., (plus (reg) (const)).
 	 L1 cache latency is about two instructions.  */
       *total = !speed ? COSTS_N_INSNS (1) + 1 : COSTS_N_INSNS (2);
-      if (SLOW_UNALIGNED_ACCESS (mode, MEM_ALIGN (x)))
+      if (rs6000_slow_unaligned_access (mode, MEM_ALIGN (x)))
 	*total += COSTS_N_INSNS (100);
       return true;
 
diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h
index 20f5b6a..4e2d0bb 100644
--- a/gcc/config/rs6000/rs6000.h
+++ b/gcc/config/rs6000/rs6000.h
@@ -968,19 +968,6 @@ enum data_align { align_abi, align_opt, align_both };
 /* Nonzero if move instructions will actually fail to work
    when given unaligned data.  */
 #define STRICT_ALIGNMENT 0
-
-/* Define this macro to be the value 1 if unaligned accesses have a cost
-   many times greater than aligned accesses, for example if they are
-   emulated in a trap handler.  */
-/* Altivec vector memory instructions simply ignore the low bits; VSX memory
-   instructions are aligned to 4 or 8 bytes.  */
-#define SLOW_UNALIGNED_ACCESS(MODE, ALIGN)				\
-  (STRICT_ALIGNMENT							\
-   || (!TARGET_EFFICIENT_UNALIGNED_VSX					\
-       && ((SCALAR_FLOAT_MODE_NOT_VECTOR_P (MODE) && (ALIGN) < 32)	\
-	   || ((VECTOR_MODE_P (MODE) || FLOAT128_VECTOR_P (MODE))	\
-	       && (int) (ALIGN) < VECTOR_ALIGN (MODE)))))
-
 
 /* Standard register usage.  */