[Bug target/19293] avr-gcc crashes when using shifts with negative shift count

[bjoern dot m dot haase at web dot de]

------- Additional Comments From bjoern dot m dot haase at web dot de  2005-01-19 21:25 -------
Hi, 
 
here is the changed patch for avr.c . I hope that it is now compliant to the 
gcc coding standards. I however did not understand what you have meant with 
"this hunk adds spurious whitespace". 
 
Yours, 
 
Björn 
 
 
Index: avr.c 
=================================================================== 
RCS file: /cvsroot/gcc/gcc/gcc/config/avr/avr.c,v 
retrieving revision 1.108.4.3 
diff -U10 -r1.108.4.3 avr.c 
--- avr.c	28 Sep 2004 01:13:55 -0000	1.108.4.3 
+++ avr.c	19 Jan 2005 21:19:49 -0000 
@@ -3288,20 +3288,27 @@ 
 const char * 
 ashrqi3_out (rtx insn, rtx operands[], int *len) 
 { 
   if (GET_CODE (operands[2]) == CONST_INT) 
     { 
       int k; 
  
       if (!len) 
 	len = &k; 
  
+      /* Test for illegal or strange shift count.  */       
+      if ( (INTVAL (operands[2]) <= 0 ) || ( INTVAL (operands[2]) > 7) ) 
+       {  
+         *len = 0; 
+         return ""; 
+       } 
+ 
       switch (INTVAL (operands[2])) 
 	{ 
 	case 1: 
 	  *len = 1; 
 	  return AS1 (asr,%0); 
  
 	case 2: 
 	  *len = 2; 
 	  return (AS1 (asr,%0) CR_TAB 
 		  AS1 (asr,%0)); 
@@ -3357,20 +3364,27 @@ 
 { 
   if (GET_CODE (operands[2]) == CONST_INT) 
     { 
       int scratch = (GET_CODE (PATTERN (insn)) == PARALLEL); 
       int ldi_ok = test_hard_reg_class (LD_REGS, operands[0]); 
       int k; 
       int *t = len; 
        
       if (!len) 
 	len = &k; 
+      
+      /* Test for illegal or strange shift count.  */  
+      if ( (INTVAL (operands[2]) <= 0) || (INTVAL (operands[2]) > 15) ) 
+        {  
+          *len = 0; 
+          return ""; 
+        } 
  
       switch (INTVAL (operands[2])) 
 	{ 
 	case 4: 
 	case 5: 
 	  /* XXX try to optimize this too? */ 
 	  break; 
  
 	case 6: 
 	  if (optimize_size) 
@@ -3517,21 +3531,27 @@ 
 const char * 
 ashrsi3_out (rtx insn, rtx operands[], int *len) 
 { 
   if (GET_CODE (operands[2]) == CONST_INT) 
     { 
       int k; 
       int *t = len; 
        
       if (!len) 
 	len = &k; 
-       
+ 
+      /* Test for illegal or strange shift count.  */ 
+      if ((INTVAL (operands[2]) <= 0) || (INTVAL (operands[2])>31))  
+        {  
+          *len = 0; 
+          return ""; 
+        }      
       switch (INTVAL (operands[2])) 
 	{ 
 	case 8: 
 	  { 
 	    int reg0 = true_regnum (operands[0]); 
 	    int reg1 = true_regnum (operands[1]); 
 	    *len=6; 
 	    if (reg0 <= reg1) 
 	      return (AS2 (mov,%A0,%B1) CR_TAB 
 		      AS2 (mov,%B0,%C1) CR_TAB 
@@ -3633,20 +3653,27 @@ 
 const char * 
 lshrqi3_out (rtx insn, rtx operands[], int *len) 
 { 
   if (GET_CODE (operands[2]) == CONST_INT) 
     { 
       int k; 
  
       if (!len) 
 	len = &k; 
        
+      /* Test for illegal or not useful shift count.  */ 
+      if ( (INTVAL (operands[2]) <= 0) | (INTVAL (operands[2]) > 7) )  
+        {  
+          *len = 0; 
+          return ""; 
+        } 
+ 
       switch (INTVAL (operands[2])) 
 	{ 
 	default: 
 	  *len = 1; 
 	  return AS1 (clr,%0); 
  
 	case 1: 
 	  *len = 1; 
 	  return AS1 (lsr,%0); 
  
@@ -3719,29 +3746,36 @@ 
 		      insn, operands, len, 1); 
   return ""; 
 } 
  
 /* 16bit logic shift right ((unsigned short)x >> i) */ 
  
 const char * 
 lshrhi3_out (rtx insn, rtx operands[], int *len) 
 { 
   if (GET_CODE (operands[2]) == CONST_INT) 
-    { 
+    {  
       int scratch = (GET_CODE (PATTERN (insn)) == PARALLEL); 
       int ldi_ok = test_hard_reg_class (LD_REGS, operands[0]); 
       int k; 
       int *t = len; 
  
       if (!len) 
 	len = &k; 
        
+      /* Test for illegal or not useful shift count.  */  
+      if ((INTVAL (operands[2]) <= 0) || (INTVAL (operands[2]) > 15))  
+       {  
+         *len = 0; 
+         return ""; 
+       } 
+        
       switch (INTVAL (operands[2])) 
 	{ 
 	case 4: 
 	  if (optimize_size && scratch) 
 	    break;  /* 5 */ 
 	  if (ldi_ok) 
 	    { 
 	      *len = 6; 
 	      return (AS1 (swap,%B0)      CR_TAB 
 		      AS1 (swap,%A0)      CR_TAB 
@@ -3977,20 +4011,27 @@ 
 const char * 
 lshrsi3_out (rtx insn, rtx operands[], int *len) 
 { 
   if (GET_CODE (operands[2]) == CONST_INT) 
     { 
       int k; 
       int *t = len; 
        
       if (!len) 
 	len = &k; 
+      
+      /* Test for illegal or not useful shift counts.  */  
+      if ((INTVAL (operands[2]) <= 0) || (INTVAL (operands[2]) > 31)) 
+        {  
+          *len = 0; 
+          return ""; 
+        }; 
        
       switch (INTVAL (operands[2])) 
 	{ 
 	case 8: 
 	  { 
 	    int reg0 = true_regnum (operands[0]); 
 	    int reg1 = true_regnum (operands[1]); 
 	    *len = 4; 
 	    if (reg0 <= reg1) 
 	      return (AS2 (mov,%A0,%B1) CR_TAB 
 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19293