mirrors/binutils-gdb
0
0
Fork 0
mirror of https://sourceware.org/git/binutils-gdb.git synced 2024-12-26 10:43:31 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

* gencode.c (process_instructions): Correct shift count for 32

Browse Source 
bit shift instructions.  Correct sign extension for arithmetic
	shifts to not shift the number of bits in the type.
This commit is contained in:
Ian Lance Taylor 1996-09-19 21:55:10 +00:00
parent cc5201d78c
commit 47c6ce6c2d
2 changed files with 9 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
sim/mips/ChangeLog
View File

@ -1,7 +1,9 @@
Thu Sep 19 15:34:17 1996 Ian Lance Taylor <ian@cygnus.com>
* gencode.c (process_instructions): Correct handling of nor
instruction.
instruction. Correct shift count for 32 bit shift instructions.
Correct sign extension for arithmetic shifts to not shift the
number of bits in the type.
Mon Sep 16 11:38:16 1996 James G. Smith <jsmith@cygnus.co.uk>

9
sim/mips/gencode.c
View File

@ -1134,7 +1134,7 @@ process_instructions(doarch,features)
/* If HI32 specified, then shift range is 32..63 */
if (MIPS_DECODE[loop].flags & HI32)
printf(" op1 |= (1 << 6);\n");
printf(" op1 |= (1 << 5);\n");
/* We do not need to perform pre-masking with 0xFFFFFFFF when
dealing with 32bit shift lefts, since the sign-extension
@ -1144,9 +1144,12 @@ process_instructions(doarch,features)
else
printf(" GPR[destreg] = ((uword64)(op2%s) >> op1);\n",((bits == 32) ? " & 0xFFFFFFFF" : ""));
/* For ARITHMETIC shifts, we must duplicate the sign-bit */
/* For ARITHMETIC shifts, we must duplicate the sign-bit. We
don't do this if op1 is zero, since it is not needed and
since that would cause an undefined shift of the number of
bits in the type. */
if (MIPS_DECODE[loop].flags & ARITHMETIC)
printf(" GPR[destreg] |= ((op2 & ((%s)1 << %d)) ? ((((%s)1 << (op1 + 1)) - 1) << (%d - op1)) : 0);\n",ltype,(bits - 1),ltype,(bits - 1));
printf(" GPR[destreg] |= (op1 != 0 && (op2 & ((%s)1 << %d)) ? ((((%s)1 << op1) - 1) << (%d - op1)) : 0);\n",ltype,(bits - 1),ltype,bits);
/* Ensure WORD values are sign-extended into 64bit registers */
if ((bits == 32) && (gprlen == 64))