[Qemu-devel] [PATCH 1/4] target-arm: Remove redundant setting of IT bits before Thumb SWI

[Peter Maydell <peter.maydell@linaro.org>]

Remove a redundant call to gen_set_condexec() in the translation of Thumb
mode SWI. (SWI and WFI generate "exceptions" which happen after the
execution of the instruction, ie when PC and IT bits have updated.
So the condexec bits at this point are not correct. However, the code
that handles finishing the translation of the TB will write the correct
value of the condexec bits later, so the only effect was that a conditional
Thumb SWI would generate slightly worse code than necessary.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target-arm/translate.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/target-arm/translate.c b/target-arm/translate.c
index 2ce82f3..4abece1 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -9014,7 +9014,6 @@ static void disas_thumb_insn(CPUState *env, DisasContext *s)
 
         if (cond == 0xf) {
             /* swi */
-            gen_set_condexec(s);
             gen_set_pc_im(s->pc);
             s->is_jmp = DISAS_SWI;
             break;
-- 
1.7.1