On Mon, 15 Jun 2015, Janne Grunau wrote:
On 2015-06-13 11:03:42 +0300, Martin Storsjö wrote:
---
gas-preprocessor.pl | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/gas-preprocessor.pl b/gas-preprocessor.pl
index 7ba31fe..4407f45 100755
--- a/gas-preprocessor.pl
+++ b/gas-preprocessor.pl
@@ -947,8 +947,8 @@ sub handle_serialized_line {
s/mov\s*pc\s*,\s*lr/bx lr/g;
# Convert stmdb/ldmia with only one register into a plain str/ldr with
post-increment/decrement
please add "wide thumb2 encoding requires at least two registers in
register list while all other encodings support one register too" to the
comment.
Ok
- $line =~ s/stmdb\s+sp!\s*,\s*\{([^,-]+)\}/str $1, [sp, #-4]!/g;
- $line =~ s/ldmia\s+sp!\s*,\s*\{([^,-]+)\}/ldr $1, [sp], #4/g;
+ $line =~ s/stm(?:db|fd)\s+sp!\s*,\s*\{([^,-]+)\}/str $1, [sp, #-4]!/g;
+ $line =~ s/ldm(?:ia|fd)\s+sp!\s*,\s*\{([^,-]+)\}/ldr $1, [sp], #4/g;
please handle the UAL syntax ldm/stm too while you're at it
Hmm, so just a ? after the (?:db|fd) group?
Is a plain "stm sp!, {...}" supposed to subtract, not add? I tested the
following snippet with gas:
.text
# .thumb
.syntax unified
stm sp!, {r1}
stmia sp!, {r1}
stmdb sp!, {r1}
stmfd sp!, {r1}
In ARM mode, the stm assembles in the same way as stmia, i.e. ascending,
not descending. In thumb mode, however, the stm and stmia assemble into
"str.w r1, [sp, #-4]!", while the stmdb/stmfd assemble into "push {r1}"
(which is functionally equivalent).
So the stm instruction (and stmia as well) seems to adjust the base
register in different direction (but only if the base register is sp)
depending on arm/thumb mode, even if .syntax unified is used.
// Martin
_______________________________________________
libav-devel mailing list
[email protected]
https://lists.libav.org/mailman/listinfo/libav-devel
