RISC-V: Fix bootstrap failure.

	gcc/
	PR bootstrap/84856
	* config/riscv/riscv.c (riscv_function_arg_boundary): Use
	PREFERRED_STACK_BOUNDARY instead of STACK_BOUNDARY.
	(riscv_first_stack_step): Likewise.
	(riscv_option_override): Use STACK_BOUNDARY instead of
	MIN_STACK_BOUNDARY.
	* config/riscv/riscv.h (STACK_BOUNDARY): Renamed from
	MIN_STACK_BOUNDARY.
	(BIGGEST_ALIGNMENT): Set to 128.
	(PREFERRED_STACK_BOUNDARY): Renamed from STACK_BOUNDARY.
	(RISCV_STACK_ALIGN): Use PREFERRED_STACK_BOUNDARY instead of
	STACK_BOUNDARY.

From-SVN: r258650

gcc/ChangeLog

+2018-03-19  Jim Wilson  <jimw@sifive.com>
+
+	PR bootstrap/84856
+	* config/riscv/riscv.c (riscv_function_arg_boundary): Use
+	PREFERRED_STACK_BOUNDARY instead of STACK_BOUNDARY.
+	(riscv_first_stack_step): Likewise.
+	(riscv_option_override): Use STACK_BOUNDARY instead of
+	MIN_STACK_BOUNDARY.
+	* config/riscv/riscv.h (STACK_BOUNDARY): Renamed from
+	MIN_STACK_BOUNDARY.
+	(BIGGEST_ALIGNMENT): Set to 128.
+	(PREFERRED_STACK_BOUNDARY): Renamed from STACK_BOUNDARY.
+	(RISCV_STACK_ALIGN): Use PREFERRED_STACK_BOUNDARY instead of
+	STACK_BOUNDARY.
+
 2018-03-19  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/84933

gcc/config/riscv/riscv.c

@@ -2202,7 +2202,7 @@ riscv_expand_conditional_branch (rtx label, rtx_code code, rtx op0, rtx op1)
 
 /* Implement TARGET_FUNCTION_ARG_BOUNDARY.  Every parameter gets at
    least PARM_BOUNDARY bits of alignment, but will be given anything up
-   to STACK_BOUNDARY bits if the type requires it.  */
+   to PREFERRED_STACK_BOUNDARY bits if the type requires it.  */
 
 static unsigned int
 riscv_function_arg_boundary (machine_mode mode, const_tree type)
@@ -2215,7 +2215,7 @@ riscv_function_arg_boundary (machine_mode mode, const_tree type)
   else
     alignment = type ? TYPE_ALIGN (type) : GET_MODE_ALIGNMENT (mode);
 
-  return MIN (STACK_BOUNDARY, MAX (PARM_BOUNDARY, alignment));
+  return MIN (PREFERRED_STACK_BOUNDARY, MAX (PARM_BOUNDARY, alignment));
 }
 
 /* If MODE represents an argument that can be passed or returned in
@@ -3506,7 +3506,7 @@ riscv_first_stack_step (struct riscv_frame_info *frame)
     return frame->total_size;
 
   HOST_WIDE_INT min_first_step = frame->total_size - frame->fp_sp_offset;
-  HOST_WIDE_INT max_first_step = IMM_REACH / 2 - STACK_BOUNDARY / 8;
+  HOST_WIDE_INT max_first_step = IMM_REACH / 2 - PREFERRED_STACK_BOUNDARY / 8;
   HOST_WIDE_INT min_second_step = frame->total_size - max_first_step;
   gcc_assert (min_first_step <= max_first_step);
 
@@ -4142,7 +4142,7 @@ riscv_option_override (void)
   riscv_stack_boundary = ABI_STACK_BOUNDARY;
   if (riscv_preferred_stack_boundary_arg)
     {
-      int min = ctz_hwi (MIN_STACK_BOUNDARY / 8);
+      int min = ctz_hwi (STACK_BOUNDARY / 8);
       int max = 8;
 
       if (!IN_RANGE (riscv_preferred_stack_boundary_arg, min, max))

gcc/config/riscv/riscv.h

@@ -124,13 +124,13 @@ along with GCC; see the file COPYING3.  If not see
 #define FUNCTION_BOUNDARY (TARGET_RVC ? 16 : 32)
 
 /* The smallest supported stack boundary the calling convention supports.  */
-#define MIN_STACK_BOUNDARY (2 * BITS_PER_WORD)
+#define STACK_BOUNDARY (2 * BITS_PER_WORD)
 
 /* The ABI stack alignment.  */
 #define ABI_STACK_BOUNDARY 128
 
 /* There is no point aligning anything to a rounder boundary than this.  */
-#define BIGGEST_ALIGNMENT STACK_BOUNDARY
+#define BIGGEST_ALIGNMENT 128
 
 /* The user-level ISA permits unaligned accesses, but they are not required
    of the privileged architecture.  */
@@ -482,7 +482,7 @@ enum reg_class
    `crtl->outgoing_args_size'.  */
 #define OUTGOING_REG_PARM_STACK_SPACE(FNTYPE) 1
 
-#define STACK_BOUNDARY riscv_stack_boundary
+#define PREFERRED_STACK_BOUNDARY riscv_stack_boundary
 
 /* Symbolic macros for the registers used to return integer and floating
    point values.  */
@@ -540,7 +540,7 @@ typedef struct {
 
 /* Align based on stack boundary, which might have been set by the user.  */
 #define RISCV_STACK_ALIGN(LOC) \
-  (((LOC) + ((STACK_BOUNDARY/8)-1)) & -(STACK_BOUNDARY/8))
+  (((LOC) + ((PREFERRED_STACK_BOUNDARY/8)-1)) & -(PREFERRED_STACK_BOUNDARY/8))
 
 /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
    the stack pointer does not matter.  The value is tested only in