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Fix miscompilation of testcase 20021010-1.c for v850 target with -O -mv850e.

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* cse.c (fold_rtx): Don't perform associative optimization for DIV and
	UDIV.

From-SVN: r58026
This commit is contained in:
Jim Wilson 2002-10-10 19:40:34 +00:00 committed by Jim Wilson
parent 61fdde38f0
commit f930bfd067
2 changed files with 16 additions and 5 deletions
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5
gcc/ChangeLog
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@ -1,3 +1,8 @@
2002-10-10 Jim Wilson <wilson@redhat.com>
* cse.c (fold_rtx): Don't perform associative optimization for DIV and
UDIV.
2002-10-10 David Edelsohn <edelsohn@gnu.org>
* config/rs6000/aix52.h: New file.

16
gcc/cse.c
View File

@ -4212,7 +4212,7 @@ fold_rtx (x, insn)
from_plus:
case SMIN: case SMAX: case UMIN: case UMAX:
case IOR: case AND: case XOR:
case MULT: case DIV: case UDIV:
case MULT:
case ASHIFT: case LSHIFTRT: case ASHIFTRT:
/* If we have (<op> <reg> <const_int>) for an associative OP and REG
is known to be of similar form, we may be able to replace the
@ -4260,11 +4260,9 @@ fold_rtx (x, insn)
break;
/* Compute the code used to compose the constants. For example,
A/C1/C2 is A/(C1 * C2), so if CODE == DIV, we want MULT. */
A-C1-C2 is A-(C1 + C2), so if CODE == MINUS, we want PLUS. */
associate_code
= (code == MULT || code == DIV || code == UDIV ? MULT
: is_shift || code == PLUS || code == MINUS ? PLUS : code);
associate_code = (is_shift || code == MINUS ? PLUS : code);
new_const = simplify_binary_operation (associate_code, mode,
const_arg1, inner_const);
@ -4302,6 +4300,14 @@ fold_rtx (x, insn)
}
break;
case DIV: case UDIV:
/* ??? The associative optimization performed immediately above is
also possible for DIV and UDIV using associate_code of MULT.
However, we would need extra code to verify that the
multiplication does not overflow, that is, there is no overflow
in the calculation of new_const. */
break;
default:
break;
}