[PATCH] sim: mips: call Unpredictable instead of setting bogus values [PR sim/29276]

Mike Frysinger vapier@gentoo.org
Fri Nov 4 00:41:04 GMT 2022


The intention of this code seems to be to indicate that this insn
should not be used and produces undefined behavior, so instead of
setting registers to bogus values, call Unpredictable.  This fixes
build warnings due to 32-bit/64-bit type conversions, and outputs
a log message for users at runtime instead of silent corruption.

Bug: https://sourceware.org/PR29276
---
 sim/mips/mips.igen | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sim/mips/mips.igen b/sim/mips/mips.igen
index dfad42276155..0746a52d5ab1 100644
--- a/sim/mips/mips.igen
+++ b/sim/mips/mips.igen
@@ -1450,7 +1450,7 @@
   else if ((fs & 0x1) == 0)
     GPR[rt] = SET64HI (FGR[fs+1]) | FGR[fs];
   else
-    GPR[rt] = SET64HI (0xDEADC0DE) | 0xBAD0BAD0;
+    Unpredictable ();
   TRACE_ALU_RESULT (GPR[rt]);
 }
 
@@ -5782,7 +5782,7 @@
   else if ((FS & 0x1) == 0)
     v = SET64HI (FGR[FS+1]) | FGR[FS];
   else
-    v = SET64HI (0xDEADC0DE) | 0xBAD0BAD0;
+    Unpredictable ();
   PENDING_FILL (RT, v);
   TRACE_ALU_RESULT (v);
 }
-- 
2.38.1



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