From: Simon Marchi <simon.marchi@efficios.com>
To: gdb-patches@sourceware.org
Cc: Simon Marchi <simon.marchi@efficios.com>
Subject: [PATCH] gdb: fix -Wtautological-overlap-compare error in lm32-tdep.c
Date: Fri, 15 May 2020 18:28:57 -0400 [thread overview]
Message-ID: <20200515222857.12514-1-simon.marchi@efficios.com> (raw)
Building with clang 11, we get:
/home/smarchi/src/binutils-gdb/gdb/lm32-tdep.c:84:44: error: overlapping comparisons always evaluate to false [-Werror,-Wtautological-overlap-compare]
return ((regnum >= SIM_LM32_EA_REGNUM) && (regnum <= SIM_LM32_BA_REGNUM))
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Indeed, this doesn't make sense, as EA_REGNUM is greater than BA_REGNUM.
I'll assume that it was just a mistake and that these two should be
swapped.
The regnums for BA and EA are contiguous, so ultimately this particular
part of the condition is only true if regnum is == EA or == BA. These
registers are Exception Address and Breakpoint Address, so I guess it
makes sense for them to be in the system register group.
The relevant reference is here:
https://www.latticesemi.com/-/media/LatticeSemi/Documents/UserManuals/JL/LatticeMico32ProcessorReferenceManual39.ashx?document_id=52077
gdb/ChangeLog:
* lm32-tdep.c (lm32_register_reggroup_p): Fix condition.
---
gdb/lm32-tdep.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gdb/lm32-tdep.c b/gdb/lm32-tdep.c
index 6b5bb1507ff3..73f8ae746f78 100644
--- a/gdb/lm32-tdep.c
+++ b/gdb/lm32-tdep.c
@@ -81,7 +81,7 @@ lm32_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
return ((regnum >= SIM_LM32_R0_REGNUM) && (regnum <= SIM_LM32_RA_REGNUM))
|| (regnum == SIM_LM32_PC_REGNUM);
else if (group == system_reggroup)
- return ((regnum >= SIM_LM32_EA_REGNUM) && (regnum <= SIM_LM32_BA_REGNUM))
+ return ((regnum >= SIM_LM32_BA_REGNUM) && (regnum <= SIM_LM32_EA_REGNUM))
|| ((regnum >= SIM_LM32_EID_REGNUM) && (regnum <= SIM_LM32_IP_REGNUM));
return default_register_reggroup_p (gdbarch, regnum, group);
}
--
2.26.2
next reply other threads:[~2020-05-15 22:28 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-15 22:28 Simon Marchi [this message]
2020-05-21 17:32 ` Simon Marchi
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