expmed.c (extract_bit_field): Update function comment regarding alt_rtl.

2019-09-09  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        * expmed.c (extract_bit_field): Update function comment
        regarding alt_rtl.
        * expr.c (expand_expr_real): Update function comment
        regarding alt_rtl.
        (expand_misaligned_mem_ref): New helper function.
        (expand_expr_real_2): Use expand_misaligned_mem_ref.
        Remove duplicate assignment to "base" at case MEM_REF.
        Remove a shadowed variable "unsignedp" at case VCE.

From-SVN: r275541

3 files changed, 60 insertions, 69 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 24e4fba..fcf052a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2019-09-09  Bernd Edlinger  <bernd.edlinger@hotmail.de>
+
+	* expmed.c (extract_bit_field): Update function comment
+	regarding alt_rtl.
+	* expr.c (expand_expr_real): Update function comment
+	regarding alt_rtl.
+	(expand_misaligned_mem_ref): New helper function.
+	(expand_expr_real_2): Use expand_misaligned_mem_ref.
+	Remove duplicate assignment to "base" at case MEM_REF.
+	Remove a shadowed variable "unsignedp" at case VCE. 
+
 2019-09-09  Richard Sandiford  <richard.sandiford@arm.com>
 
 	* regset.h (regs_invalidated_by_call_regset): Delete.
diff --git a/gcc/expmed.c b/gcc/expmed.c
index c582f3a..f1975fe 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -2046,7 +2046,10 @@ extract_integral_bit_field (rtx op0, opt_scalar_int_mode op0_mode,
    If a TARGET is specified and we can store in it at no extra cost,
    we do so, and return TARGET.
    Otherwise, we return a REG of mode TMODE or MODE, with TMODE preferred
-   if they are equally easy.  */
+   if they are equally easy.
+
+   If the result can be stored at TARGET, and ALT_RTL is non-NULL,
+   then *ALT_RTL is set to TARGET (before legitimziation).  */
 
 rtx
 extract_bit_field (rtx str_rtx, poly_uint64 bitsize, poly_uint64 bitnum,
diff --git a/gcc/expr.c b/gcc/expr.c
index 3f4c98c..2f2b53f 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -8261,6 +8261,8 @@ expand_constructor (tree exp, rtx target, enum expand_modifier modifier,
    DECL_RTL of the VAR_DECL.  *ALT_RTL is also set if EXP is a
    COMPOUND_EXPR whose second argument is such a VAR_DECL, and so on
    recursively.
+   If the result can be stored at TARGET, and ALT_RTL is non-NULL,
+   then *ALT_RTL is set to TARGET (before legitimziation).
 
    If INNER_REFERENCE_P is true, we are expanding an inner reference.
    In this case, we don't adjust a returned MEM rtx that wouldn't be
@@ -8398,6 +8400,40 @@ expand_cond_expr_using_cmove (tree treeop0 ATTRIBUTE_UNUSED,
   return NULL_RTX;
 }
 
+/* A helper function for expand_expr_real_2 to be used with a
+   misaligned mem_ref TEMP.  Assume an unsigned type if UNSIGNEDP
+   is nonzero, with alignment ALIGN in bits.
+   Store the value at TARGET if possible (if TARGET is nonzero).
+   Regardless of TARGET, we return the rtx for where the value is placed.
+   If the result can be stored at TARGET, and ALT_RTL is non-NULL,
+   then *ALT_RTL is set to TARGET (before legitimziation).  */
+
+static rtx
+expand_misaligned_mem_ref (rtx temp, machine_mode mode, int unsignedp,
+			   unsigned int align, rtx target, rtx *alt_rtl)
+{
+  enum insn_code icode;
+
+  if ((icode = optab_handler (movmisalign_optab, mode))
+      != CODE_FOR_nothing)
+    {
+      class expand_operand ops[2];
+
+      /* We've already validated the memory, and we're creating a
+	 new pseudo destination.  The predicates really can't fail,
+	 nor can the generator.  */
+      create_output_operand (&ops[0], NULL_RTX, mode);
+      create_fixed_operand (&ops[1], temp);
+      expand_insn (icode, 2, ops);
+      temp = ops[0].value;
+    }
+  else if (targetm.slow_unaligned_access (mode, align))
+    temp = extract_bit_field (temp, GET_MODE_BITSIZE (mode),
+			      0, unsignedp, target,
+			      mode, mode, false, alt_rtl);
+  return temp;
+}
+
 rtx
 expand_expr_real_2 (sepops ops, rtx target, machine_mode tmode,
 		    enum expand_modifier modifier)
@@ -10077,27 +10113,8 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode,
 	      && !inner_reference_p
 	      && mode != BLKmode
 	      && MEM_ALIGN (temp) < GET_MODE_ALIGNMENT (mode))
-	    {
-	      enum insn_code icode;
-
-	      if ((icode = optab_handler (movmisalign_optab, mode))
-		  != CODE_FOR_nothing)
-		{
-		  class expand_operand ops[2];
-
-		  /* We've already validated the memory, and we're creating a
-		     new pseudo destination.  The predicates really can't fail,
-		     nor can the generator.  */
-		  create_output_operand (&ops[0], NULL_RTX, mode);
-		  create_fixed_operand (&ops[1], temp);
-		  expand_insn (icode, 2, ops);
-		  temp = ops[0].value;
-		}
-	      else if (targetm.slow_unaligned_access (mode, MEM_ALIGN (temp)))
-		temp = extract_bit_field (temp, GET_MODE_BITSIZE (mode),
-					  0, unsignedp, NULL_RTX,
-					  mode, mode, false, NULL);
-	    }
+	    temp = expand_misaligned_mem_ref (temp, mode, unsignedp,
+					      MEM_ALIGN (temp), NULL_RTX, NULL);
 
 	  return temp;
 	}
@@ -10325,27 +10342,8 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode,
 	    && modifier != EXPAND_MEMORY
 	    && mode != BLKmode
 	    && align < GET_MODE_ALIGNMENT (mode))
-	  {
-	    enum insn_code icode;
-
-	    if ((icode = optab_handler (movmisalign_optab, mode))
-		!= CODE_FOR_nothing)
-	      {
-		class expand_operand ops[2];
-
-		/* We've already validated the memory, and we're creating a
-		   new pseudo destination.  The predicates really can't fail,
-		   nor can the generator.  */
-		create_output_operand (&ops[0], NULL_RTX, mode);
-		create_fixed_operand (&ops[1], temp);
-		expand_insn (icode, 2, ops);
-		temp = ops[0].value;
-	      }
-	    else if (targetm.slow_unaligned_access (mode, align))
-	      temp = extract_bit_field (temp, GET_MODE_BITSIZE (mode),
-					0, unsignedp, NULL_RTX,
-					mode, mode, false, NULL);
-	  }
+	  temp = expand_misaligned_mem_ref (temp, mode, unsignedp,
+					    align, NULL_RTX, NULL);
 	return temp;
       }
 
@@ -10357,7 +10355,6 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode,
 	machine_mode address_mode;
 	tree base = TREE_OPERAND (exp, 0);
 	gimple *def_stmt;
-	enum insn_code icode;
 	unsigned align;
 	/* Handle expansion of non-aliased memory with non-BLKmode.  That
 	   might end up in a register.  */
@@ -10387,7 +10384,6 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode,
 	    return expand_expr (exp, target, tmode, modifier);
 	  }
 	address_mode = targetm.addr_space.address_mode (as);
-	base = TREE_OPERAND (exp, 0);
 	if ((def_stmt = get_def_for_expr (base, BIT_AND_EXPR)))
 	  {
 	    tree mask = gimple_assign_rhs2 (def_stmt);
@@ -10414,27 +10410,9 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode,
 	    && !inner_reference_p
 	    && mode != BLKmode
 	    && align < GET_MODE_ALIGNMENT (mode))
-	  {
-	    if ((icode = optab_handler (movmisalign_optab, mode))
-		!= CODE_FOR_nothing)
-	      {
-		class expand_operand ops[2];
-
-		/* We've already validated the memory, and we're creating a
-		   new pseudo destination.  The predicates really can't fail,
-		   nor can the generator.  */
-		create_output_operand (&ops[0], NULL_RTX, mode);
-		create_fixed_operand (&ops[1], temp);
-		expand_insn (icode, 2, ops);
-		temp = ops[0].value;
-	      }
-	    else if (targetm.slow_unaligned_access (mode, align))
-	      temp = extract_bit_field (temp, GET_MODE_BITSIZE (mode),
-					0, TYPE_UNSIGNED (TREE_TYPE (exp)),
-					(modifier == EXPAND_STACK_PARM
-					 ? NULL_RTX : target),
-					mode, mode, false, alt_rtl);
-	  }
+	  temp = expand_misaligned_mem_ref (temp, mode, unsignedp, align,
+					    modifier == EXPAND_STACK_PARM
+					    ? NULL_RTX : target, alt_rtl);
 	if (reverse
 	    && modifier != EXPAND_MEMORY
 	    && modifier != EXPAND_WRITE)
@@ -11109,11 +11087,10 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode,
 	machine_mode mode1;
 	poly_int64 bitsize, bitpos, bytepos;
 	tree offset;
-	int unsignedp, reversep, volatilep = 0;
+	int reversep, volatilep = 0;
 	tree tem
 	  = get_inner_reference (treeop0, &bitsize, &bitpos, &offset, &mode1,
 				 &unsignedp, &reversep, &volatilep);
-	rtx orig_op0;
 
 	/* ??? We should work harder and deal with non-zero offsets.  */
 	if (!offset
@@ -11123,7 +11100,7 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode,
 	    && known_eq (wi::to_poly_offset (TYPE_SIZE (type)), bitsize))
 	  {
 	    /* See the normal_inner_ref case for the rationale.  */
-	    orig_op0
+	    rtx orig_op0
 	      = expand_expr_real (tem,
 				  (TREE_CODE (TREE_TYPE (tem)) == UNION_TYPE
 				   && (TREE_CODE (TYPE_SIZE (TREE_TYPE (tem)))