Re: [PATCH 4/6] nios2: Fixes for RTL checking

[Sandra Loosemore <sandra@codesourcery.com>]

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On 02/21/2017 12:41 PM, Sandra Loosemore wrote:
> On 02/21/2017 07:48 AM, Segher Boessenkool wrote:
>> You cannot call REGNO on something that isn't a REG, and you cannot
>> call INTVAL on something that isn't a CONST_INT.
>>
>> The way I fixed nios2_alternate_compare_const is admittedly a bit lame.
>
> Yeah.  :-P
>
>> 2017-02-21  Segher Boessenkool  <segher@kernel.crashing.org>
>>
>>     * config/nios2/nios2.c (nios2_simple_const_p): Returns false if the
>>     argument isn't a CONST_INT.
>>     (nios2_alternate_compare_const): Set *alt_code and *alt_op to code
>>     and op if op is not a CONST_INT.
>>     (nios2_valid_compare_const_p): Return false if the argument isn't
>>     a CONST_INT.
>>     (ldstwm_operation_p): Return false if first_base is not a REG or
>>     if first_offset is not a CONST_INT.
>
> Give me a couple days to fiddle with this a bit and run regression tests.
>
> -Sandra
>

I've checked in the attached version of the patch.  I basically moved 
the CONST_INT test into nios2_validate_compare and changed its two 
helper functions to assert if they get the wrong thing, instead of 
trying to make them cope with other cases.

I regression-tested this on nios2-elf and did some tests on 
nios2-linux-gnu as well.

Thanks, Segher, for identifying these bugs.

-Sandra


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2017-02-24  Segher Boessenkool  <segher@kernel.crashing.org>
	    Sandra Loosemore  <sandra@codesourcery.com>

	gcc/
	* config/nios2/nios2.c (nios2_simple_const_p): Returns false if the
	argument isn't a CONST_INT.
	(nios2_alternate_compare_const): Assert op is a CONST_INT.
	(nios2_valid_compare_const_p): Assert op is a CONST_INT.
	(nios2_validate_compare): Bypass alternate compare logic if *op2
	is not a CONST_INT.
	(ldstwm_operation_p): Return false if first_base is not a REG or
	if first_offset is not a CONST_INT.


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Index: gcc/config/nios2/nios2.c
===================================================================
--- gcc/config/nios2/nios2.c	(revision 245646)
+++ gcc/config/nios2/nios2.c	(working copy)
@@ -1416,6 +1416,8 @@ nios2_option_override (void)
 static bool
 nios2_simple_const_p (const_rtx cst)
 {
+  if (!CONST_INT_P (cst))
+    return false;
   HOST_WIDE_INT val = INTVAL (cst);
   return SMALL_INT (val) || SMALL_INT_UNSIGNED (val) || UPPER16_INT (val);
 }
@@ -1753,6 +1755,8 @@ nios2_alternate_compare_const (enum rtx_
 			       enum rtx_code *alt_code, rtx *alt_op,
 			       machine_mode mode)
 {
+  gcc_assert (CONST_INT_P (op));
+
   HOST_WIDE_INT opval = INTVAL (op);
   enum rtx_code scode = signed_condition (code);
   bool dec_p = (scode == LT || scode == GE);
@@ -1788,6 +1792,7 @@ nios2_alternate_compare_const (enum rtx_
 static bool
 nios2_valid_compare_const_p (enum rtx_code code, rtx op)
 {
+  gcc_assert (CONST_INT_P (op));
   switch (code)
     {
     case EQ: case NE: case GE: case LT:
@@ -1846,7 +1851,7 @@ nios2_validate_compare (machine_mode mod
   if (GET_MODE_CLASS (mode) == MODE_FLOAT)
     return nios2_validate_fpu_compare (mode, cmp, op1, op2, true);
 
-  if (!reg_or_0_operand (*op2, mode))
+  if (CONST_INT_P (*op2) && *op2 != const0_rtx)
     {
       /* Create alternate constant compare.  */
       nios2_alternate_compare_const (code, *op2, &alt_code, &alt_op2, mode);
@@ -1878,8 +1883,11 @@ nios2_validate_compare (machine_mode mod
 	  code = alt_code;
 	  *op2 = alt_op2;
 	}
-      *op2 = force_reg (SImode, *op2);
+      *op2 = force_reg (mode, *op2);
     }
+    else if (!reg_or_0_operand (*op2, mode))
+      *op2 = force_reg (mode, *op2);
+    
  check_rebuild_cmp:
   if (code == GT || code == GTU || code == LE || code == LEU)
     {
@@ -4558,6 +4566,8 @@ ldstwm_operation_p (rtx op, bool load_p)
 	  if (!split_mem_address (XEXP (mem, 0),
 				  &first_base, &first_offset))
 	    return false;
+	  if (!REG_P (first_base) || !CONST_INT_P (first_offset))
+	    return false;
 	  base_reg = first_base;
 	  inc_p = INTVAL (first_offset) >= 0;
 	}