* [PATCH] sim: bfin: avoid left shifting negative values
@ 2024-01-07 5:24 Mike Frysinger
0 siblings, 0 replies; only message in thread
From: Mike Frysinger @ 2024-01-07 5:24 UTC (permalink / raw)
To: gdb-patches
We just want to create a bitmask here, so cast the mask to unsigned
to avoid left shifting a negative value which is undefined behavior.
---
sim/bfin/bfin-sim.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sim/bfin/bfin-sim.c b/sim/bfin/bfin-sim.c
index 1a9b499ebb4c..2e7a5632fffe 100644
--- a/sim/bfin/bfin-sim.c
+++ b/sim/bfin/bfin-sim.c
@@ -786,7 +786,7 @@ lshift (SIM_CPU *cpu, bu64 val, int cnt, int size, bool saturate, bool overflow)
However, it's a little more complex than looking at sign bits, we need
to see if we are shifting the sign information away... */
if (((val << cnt) >> size) == 0
- || (((val << cnt) >> size) == ~(~0 << cnt)
+ || (((val << cnt) >> size) == ~((bu32)~0 << cnt)
&& ((new_val >> (size - 1)) & 0x1)))
v_i = 0;
else
@@ -5880,7 +5880,7 @@ decode_dsp32shiftimm_0 (SIM_CPU *cpu, bu16 iw0, bu16 iw1)
bu16 inshift = in << shift;
if (((inshift & ~0xFFFF)
- && ((inshift & ~0xFFFF) >> 16) != ~(~0 << shift))
+ && ((inshift & ~0xFFFF) >> 16) != ~((bu32)~0 << shift))
|| (inshift & 0x8000) != (in & 0x8000))
{
if (in & 0x8000)
--
2.43.0
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