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authorJim Wilson <jimw@sifive.com>2021-04-07 18:51:52 -0700
committerJim Wilson <jimw@sifive.com>2021-04-07 18:51:52 -0700
commit0592e80bcf1bbab2fbbb110ea395f9608e4f594c (patch)
treeb175364127540032ba3a64ca889ab5d67efa82ea /sim
parentbf5271659d0d78174041aa0e198406c9ecacc7a4 (diff)
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Aarch64 sim fix for gcc-10 miscompilation.
This fixes a problem that occurs when compiled by gcc-10, as the code is relying on undefined overflow behavior. This is fixed by replacing compares between 32-bit and 64-bit results with compares that just use the 64-bit results with a cast. PR sim/27483 * simulator.c (set_flags_for_add32): Compare uresult against itself. Compare sresult against itself.
Diffstat (limited to 'sim')
-rw-r--r--sim/aarch64/ChangeLog6
-rw-r--r--sim/aarch64/simulator.c4
2 files changed, 8 insertions, 2 deletions
diff --git a/sim/aarch64/ChangeLog b/sim/aarch64/ChangeLog
index e667c47..d328fcd 100644
--- a/sim/aarch64/ChangeLog
+++ b/sim/aarch64/ChangeLog
@@ -1,3 +1,9 @@
+2021-04-07 Jim Wilson <jimw@sifive.com>
+
+ PR sim/27483
+ * simulator.c (set_flags_for_add32): Compare uresult against
+ itself. Compare sresult against itself.
+
2021-04-02 Mike Frysinger <vapier@gentoo.org>
* aclocal.m4, configure: Regenerate.
diff --git a/sim/aarch64/simulator.c b/sim/aarch64/simulator.c
index 6ba29a0..e0b428d 100644
--- a/sim/aarch64/simulator.c
+++ b/sim/aarch64/simulator.c
@@ -1650,10 +1650,10 @@ set_flags_for_add32 (sim_cpu *cpu, int32_t value1, int32_t value2)
if (result & (1 << 31))
flags |= N;
- if (uresult != (uint32_t)result)
+ if (uresult != (uint32_t)uresult)
flags |= C;
- if (sresult != result)
+ if (sresult != (int32_t)sresult)
flags |= V;
aarch64_set_CPSR (cpu, flags);