[Qemu-devel] [PATCH 12/13] target/arm: Add v8M stack checks for VLDM/VSTM

[Peter Maydell]

Add the v8M stack checks for the VLDM/VSTM
(aka VPUSH/VPOP) instructions. This code is currently
unreachable because we haven't yet implemented M profile
floating point support, but since the change is simple,
we add it now because otherwise we're likely to forget to
do it later.

Signed-off-by: Peter Maydell <address@hidden>
---
 target/arm/translate.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/target/arm/translate.c b/target/arm/translate.c
index ef64d2559de..2d3a1be518b 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -4229,6 +4229,18 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn)
                 if (insn & (1 << 24)) /* pre-decrement */
                     tcg_gen_addi_i32(addr, addr, -((insn & 0xff) << 2));
 
+                if (rn == 13 && w && s->v8m_stackcheck) {
+                    /*
+                     * Here 'addr' is the lowest address we will store to,
+                     * and is either the old SP (if post-increment) or
+                     * the new SP (if pre-decrement). For post-increment
+                     * where the old value is below the limit and the new
+                     * value is above, it is UNKNOWN whether the limit check
+                     * triggers; we choose to trigger.
+                     */
+                    gen_helper_v8m_stackcheck(cpu_env, addr);
+                }
+
                 if (dp)
                     offset = 8;
                 else
-- 
2.19.0