From: Tiezhu Yang <yangtiezhu@loongson.cn>
To: gdb-patches@sourceware.org
Subject: [PATCH] gdb: LoongArch: Emulate floating-point branch instructions
Date: Wed, 30 Apr 2025 15:10:15 +0800 [thread overview]
Message-ID: <20250430071015.23552-1-yangtiezhu@loongson.cn> (raw)
Add bceqz and bcnez cases in loongarch_insn_is_cond_branch() and
loongarch_next_pc() to emulate floating-point branch instructions.
Here are the references:
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#_bceqz_bcnez
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#table-table-of-instruction-encoding
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
gdb/loongarch-tdep.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/gdb/loongarch-tdep.c b/gdb/loongarch-tdep.c
index 092127dd810..d79ec686e6a 100644
--- a/gdb/loongarch-tdep.c
+++ b/gdb/loongarch-tdep.c
@@ -74,7 +74,9 @@ loongarch_insn_is_cond_branch (insn_t insn)
|| (insn & 0xfc000000) == 0x68000000 /* bltu */
|| (insn & 0xfc000000) == 0x6c000000 /* bgeu */
|| (insn & 0xfc000000) == 0x40000000 /* beqz */
- || (insn & 0xfc000000) == 0x44000000) /* bnez */
+ || (insn & 0xfc000000) == 0x44000000 /* bnez */
+ || (insn & 0xfc000300) == 0x48000000 /* bceqz */
+ || (insn & 0xfc000300) == 0x48000100) /* bcnez */
return true;
return false;
}
@@ -314,6 +316,20 @@ loongarch_next_pc (struct regcache *regcache, CORE_ADDR cur_pc)
if (rj != 0)
next_pc = cur_pc + loongarch_decode_imm ("0:5|10:16<<2", insn, 1);
}
+ else if ((insn & 0xfc000300) == 0x48000000) /* bceqz cj, offs21 */
+ {
+ LONGEST cj = regcache_raw_get_signed (regcache,
+ loongarch_decode_imm ("5:3", insn, 0) + LOONGARCH_FIRST_FCC_REGNUM);
+ if (cj == 0)
+ next_pc = cur_pc + loongarch_decode_imm ("0:5|10:16<<2", insn, 1);
+ }
+ else if ((insn & 0xfc000300) == 0x48000100) /* bcnez cj, offs21 */
+ {
+ LONGEST cj = regcache_raw_get_signed (regcache,
+ loongarch_decode_imm ("5:3", insn, 0) + LOONGARCH_FIRST_FCC_REGNUM);
+ if (cj != 0)
+ next_pc = cur_pc + loongarch_decode_imm ("0:5|10:16<<2", insn, 1);
+ }
else if ((insn & 0xffff8000) == 0x002b0000) /* syscall */
{
if (tdep->syscall_next_pc != nullptr)
--
2.42.0
next reply other threads:[~2025-04-30 7:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-30 7:10 Tiezhu Yang [this message]
2025-05-07 4:30 ` Kevin Buettner
2025-05-10 13:29 ` Tiezhu Yang
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