target/arm: Clear CONTROL_S.SFPA in SG insn if FPU present

If the floating point extension is present, then the SG instruction
must clear the CONTROL_S.SFPA bit. Implement this.

(On a no-FPU system the bit will always be zero, so we don't need
to make the clearing of the bit conditional on ARM_FEATURE_VFP.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190416125744.27770-8-peter.maydell@linaro.org

diff --git a/target/arm/helper.c b/target/arm/helper.c
index c3d5fe0..45a9d92 100644 (file)
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -8804,6 +8804,7 @@ static bool v7m_handle_execute_nsc(ARMCPU *cpu)
     qemu_log_mask(CPU_LOG_INT, "...really an SG instruction at 0x%08" PRIx32
                   ", executing it\n", env->regs[15]);
     env->regs[14] &= ~1;
+    env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
     switch_v7m_security_state(env, true);
     xpsr_write(env, 0, XPSR_IT);
     env->regs[15] += 4;