target/arm: Factor FP context update code out into helper function

Factor the code in full_vfp_access_check() which updates the
ownership of the FP context and creates a new FP context
out into its own function.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210618141019.10671-6-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2021-06-18 15:10:17 +01:00
parent e494cd0a1a
commit 95aceeeac9

View file

@ -131,6 +131,62 @@ void gen_preserve_fp_state(DisasContext *s)
}
}
/*
* Generate code for M-profile FP context handling: update the
* ownership of the FP context, and create a new context if
* necessary. This corresponds to the parts of the pseudocode
* ExecuteFPCheck() after the inital PreserveFPState() call.
*/
static void gen_update_fp_context(DisasContext *s)
{
/* Update ownership of FP context: set FPCCR.S to match current state */
if (s->v8m_fpccr_s_wrong) {
TCGv_i32 tmp;
tmp = load_cpu_field(v7m.fpccr[M_REG_S]);
if (s->v8m_secure) {
tcg_gen_ori_i32(tmp, tmp, R_V7M_FPCCR_S_MASK);
} else {
tcg_gen_andi_i32(tmp, tmp, ~R_V7M_FPCCR_S_MASK);
}
store_cpu_field(tmp, v7m.fpccr[M_REG_S]);
/* Don't need to do this for any further FP insns in this TB */
s->v8m_fpccr_s_wrong = false;
}
if (s->v7m_new_fp_ctxt_needed) {
/*
* Create new FP context by updating CONTROL.FPCA, CONTROL.SFPA,
* the FPSCR, and VPR.
*/
TCGv_i32 control, fpscr;
uint32_t bits = R_V7M_CONTROL_FPCA_MASK;
fpscr = load_cpu_field(v7m.fpdscr[s->v8m_secure]);
gen_helper_vfp_set_fpscr(cpu_env, fpscr);
tcg_temp_free_i32(fpscr);
if (dc_isar_feature(aa32_mve, s)) {
TCGv_i32 z32 = tcg_const_i32(0);
store_cpu_field(z32, v7m.vpr);
}
/*
* We don't need to arrange to end the TB, because the only
* parts of FPSCR which we cache in the TB flags are the VECLEN
* and VECSTRIDE, and those don't exist for M-profile.
*/
if (s->v8m_secure) {
bits |= R_V7M_CONTROL_SFPA_MASK;
}
control = load_cpu_field(v7m.control[M_REG_S]);
tcg_gen_ori_i32(control, control, bits);
store_cpu_field(control, v7m.control[M_REG_S]);
/* Don't need to do this for any further FP insns in this TB */
s->v7m_new_fp_ctxt_needed = false;
}
}
/*
* Check that VFP access is enabled. If it is, do the necessary
* M-profile lazy-FP handling and then return true.
@ -173,52 +229,8 @@ static bool full_vfp_access_check(DisasContext *s, bool ignore_vfp_enabled)
/* Trigger lazy-state preservation if necessary */
gen_preserve_fp_state(s);
/* Update ownership of FP context: set FPCCR.S to match current state */
if (s->v8m_fpccr_s_wrong) {
TCGv_i32 tmp;
tmp = load_cpu_field(v7m.fpccr[M_REG_S]);
if (s->v8m_secure) {
tcg_gen_ori_i32(tmp, tmp, R_V7M_FPCCR_S_MASK);
} else {
tcg_gen_andi_i32(tmp, tmp, ~R_V7M_FPCCR_S_MASK);
}
store_cpu_field(tmp, v7m.fpccr[M_REG_S]);
/* Don't need to do this for any further FP insns in this TB */
s->v8m_fpccr_s_wrong = false;
}
if (s->v7m_new_fp_ctxt_needed) {
/*
* Create new FP context by updating CONTROL.FPCA, CONTROL.SFPA,
* the FPSCR, and VPR.
*/
TCGv_i32 control, fpscr;
uint32_t bits = R_V7M_CONTROL_FPCA_MASK;
fpscr = load_cpu_field(v7m.fpdscr[s->v8m_secure]);
gen_helper_vfp_set_fpscr(cpu_env, fpscr);
tcg_temp_free_i32(fpscr);
if (dc_isar_feature(aa32_mve, s)) {
TCGv_i32 z32 = tcg_const_i32(0);
store_cpu_field(z32, v7m.vpr);
}
/*
* We don't need to arrange to end the TB, because the only
* parts of FPSCR which we cache in the TB flags are the VECLEN
* and VECSTRIDE, and those don't exist for M-profile.
*/
if (s->v8m_secure) {
bits |= R_V7M_CONTROL_SFPA_MASK;
}
control = load_cpu_field(v7m.control[M_REG_S]);
tcg_gen_ori_i32(control, control, bits);
store_cpu_field(control, v7m.control[M_REG_S]);
/* Don't need to do this for any further FP insns in this TB */
s->v7m_new_fp_ctxt_needed = false;
}
/* Update ownership of FP context and create new FP context if needed */
gen_update_fp_context(s);
}
return true;