[NIOS2] Fix disassembly of br.n instruction.

Message ID 20210324220341.555753-1-abidh@codesourcery.com
State New
Headers show
Series
  • [NIOS2] Fix disassembly of br.n instruction.
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Commit Message

Hafiz Abid Qadeer March 24, 2021, 10:03 p.m.
The code was checking wrong bit for sign extension. It caused it
to zero-extend instead of sign-extend the immediate value.

2021-03-24  Abid Qadeer  <abidh@codesourcery.com>

	opcodes/
	* nios2-dis.c (nios2_print_insn_arg): Fix sign extension of
	immediate in br.n instruction.

	gas/
	* testsuite/gas/nios2/brn.s: New.
	* testsuite/gas/nios2/brn.d: New.
---
 gas/testsuite/gas/nios2/brn.d | 10 ++++++++++
 gas/testsuite/gas/nios2/brn.s |  4 ++++
 opcodes/nios2-dis.c           |  2 +-
 3 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 gas/testsuite/gas/nios2/brn.d
 create mode 100644 gas/testsuite/gas/nios2/brn.s

-- 
2.25.1

Comments

Sandra Loosemore March 24, 2021, 10:41 p.m. | #1
On 3/24/21 4:03 PM, Hafiz Abid Qadeer wrote:
> The code was checking wrong bit for sign extension. It caused it

> to zero-extend instead of sign-extend the immediate value.

> 

> 2021-03-24  Abid Qadeer  <abidh@codesourcery.com>

> 

> 	opcodes/

> 	* nios2-dis.c (nios2_print_insn_arg): Fix sign extension of

> 	immediate in br.n instruction.

> 

> 	gas/

> 	* testsuite/gas/nios2/brn.s: New.

> 	* testsuite/gas/nios2/brn.d: New.


This is fine -- thank you!

-Sandra

Patch

diff --git a/gas/testsuite/gas/nios2/brn.d b/gas/testsuite/gas/nios2/brn.d
new file mode 100644
index 00000000000..a9ed472229a
--- /dev/null
+++ b/gas/testsuite/gas/nios2/brn.d
@@ -0,0 +1,10 @@ 
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: NIOS2 br.n
+#as: -march=r2
+
+.*: +file format elf32-littlenios2
+
+Disassembly of section .text:
+0+0000 <[^>]*> c4000020 	nop
+0+0004 <[^>]*> ff43      	br.n	00000000 <foo>
+	...
diff --git a/gas/testsuite/gas/nios2/brn.s b/gas/testsuite/gas/nios2/brn.s
new file mode 100644
index 00000000000..84d9cf1c8f1
--- /dev/null
+++ b/gas/testsuite/gas/nios2/brn.s
@@ -0,0 +1,4 @@ 
+# Source file used to test the br.n instructions
+foo:
+	nop
+	br.n foo
diff --git a/opcodes/nios2-dis.c b/opcodes/nios2-dis.c
index e1cc7169654..794d700c3e5 100644
--- a/opcodes/nios2-dis.c
+++ b/opcodes/nios2-dis.c
@@ -694,7 +694,7 @@  nios2_print_insn_arg (const char *argptr,
       switch (op->format)
 	{
 	case iw_I10_type:
-	  o = (((GET_IW_I10_IMM10 (opcode) & 0x3ff) ^ 0x400) - 0x400) * 2;
+	  o = (((GET_IW_I10_IMM10 (opcode) & 0x3ff) ^ 0x200) - 0x200) * 2;
 	  break;
 	default:
 	  bad_opcode (op);