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fix for LT comparison
- To: gcc-patches at gcc dot gnu dot org
- Subject: fix for LT comparison
- From: Geoff Keating <geoffk at cygnus dot com>
- Date: Sat, 15 Jul 2000 20:15:24 -0700
This patch fixes comparisons like
0x00000000ffffffffLL > 0
which was being considered to be false, in a 32-bit-word ->
64-bit-word cross-environment.
Bootstrapped & tested OK on x86 linux native. It's also been tested
on an older version of the tree (+ cygnus hacks) on AIX32 and AIX64,
which is where the problem appeared.
OK to commit?
--
- Geoffrey Keating <geoffk@cygnus.com>
===File ~/patches/cygnus/rs6000-simplifyLT.patch============
2000-07-08 Geoffrey Keating <geoffk@cygnus.com>
* simplify-rtx.c (simplify_relational_operation): Two signed
values with equal high words are less/greater than each other if
their low words are less/greater when considered as unsigned.
Index: simplify-rtx.c
===================================================================
RCS file: /cvs/cvsfiles/devo/gcc/simplify-rtx.c,v
retrieving revision 1.4
retrieving revision 1.4.8.1
diff -u -p -r1.4 -r1.4.8.1
--- simplify-rtx.c 2000/01/11 15:00:00 1.4
+++ simplify-rtx.c 2000/07/08 12:49:13 1.4.8.1
@@ -1689,8 +1689,8 @@ simplify_relational_operation (code, mod
}
equal = (h0u == h1u && l0u == l1u);
- op0lt = (h0s < h1s || (h0s == h1s && l0s < l1s));
- op1lt = (h1s < h0s || (h1s == h0s && l1s < l0s));
+ op0lt = (h0s < h1s || (h0s == h1s && l0u < l1u));
+ op1lt = (h1s < h0s || (h1s == h0s && l1u < l0u));
op0ltu = (h0u < h1u || (h0u == h1u && l0u < l1u));
op1ltu = (h1u < h0u || (h1u == h0u && l1u < l0u));
}
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