[Guile-commits] 08/14: Use bx instead of mov for jumps on ARM

[Andy Wingo]

wingo pushed a commit to branch master
in repository guile.

commit a6fee1add8043f54b3adfe9e539b25c69456d2d6
Author: Icecream95 <ixn@keemail.me>
AuthorDate: Thu Apr 9 21:24:51 2020 +1200

    Use bx instead of mov for jumps on ARM
---
 lightening/arm-cpu.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/lightening/arm-cpu.c b/lightening/arm-cpu.c
index 9b328ad..3cea9f8 100644
--- a/lightening/arm-cpu.c
+++ b/lightening/arm-cpu.c
@@ -2066,7 +2066,7 @@ rshi_u(jit_state_t *_jit, int32_t r0, int32_t r1, 
jit_word_t i0)
 static void
 jmpr(jit_state_t *_jit, int32_t r0)
 {
-  T1_MOV(_jit, jit_gpr_regno(_PC), r0);
+  T1_BX(_jit, r0);
 }
 
 static jit_reloc_t
@@ -3022,11 +3022,10 @@ emit_veneer(jit_state_t *_jit, jit_pointer_t target)
 {
   uint16_t thumb1_ldr = 0x4800;
   int32_t tmp = jit_gpr_regno(JIT_TMP1);
-  int32_t rd = jit_gpr_regno(_PC);
   ASSERT(tmp < 8);
   // Loaded addr is 4 bytes after the LDR, which is aligned, so offset is 0.
   emit_u16(_jit, thumb1_ldr | (tmp << 8));
-  emit_u16(_jit, THUMB_MOV|((_u4(rd)&8)<<4)|(_u4(tmp)<<3)|(rd&7));
+  emit_u16(_jit, THUMB_BX|(_u4(tmp)<<3));
   emit_u32(_jit, (uint32_t) target);
 }