[Qemu-devel] [PATCH 2/2] target-arm: Implement YIELD insn to yield in ARM and Thumb translators

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

Implement the YIELD instruction in the ARM and Thumb translators to
actually yield control back to the top level loop rather than being
a simple no-op. (We already do this for A64.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target-arm/translate.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/target-arm/translate.c b/target-arm/translate.c
index ead08f4..05da26b 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -4080,6 +4080,10 @@ static void gen_rfe(DisasContext *s, TCGv_i32 pc, TCGv_i32 cpsr)
 static void gen_nop_hint(DisasContext *s, int val)
 {
     switch (val) {
+    case 1: /* yield */
+        gen_set_pc_im(s, s->pc);
+        s->is_jmp = DISAS_YIELD;
+        break;
     case 3: /* wfi */
         gen_set_pc_im(s, s->pc);
         s->is_jmp = DISAS_WFI;
@@ -11459,6 +11463,9 @@ static inline void gen_intermediate_code_internal(ARMCPU *cpu,
         case DISAS_WFE:
             gen_helper_wfe(cpu_env);
             break;
+        case DISAS_YIELD:
+            gen_helper_yield(cpu_env);
+            break;
         case DISAS_SWI:
             gen_exception(EXCP_SWI, syn_aa32_svc(dc->svc_imm, dc->thumb),
                           default_exception_el(dc));
-- 
1.9.1