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

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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
1 changed files with 58 additions and 46 deletions
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90
target/arm/translate-vfp.c
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@ -132,47 +132,13 @@ void gen_preserve_fp_state(DisasContext *s)
} }
/* /*
* Check that VFP access is enabled. If it is, do the necessary * Generate code for M-profile FP context handling: update the
* M-profile lazy-FP handling and then return true. * ownership of the FP context, and create a new context if
* If not, emit code to generate an appropriate exception and * necessary. This corresponds to the parts of the pseudocode
* return false. * ExecuteFPCheck() after the inital PreserveFPState() call.
* The ignore_vfp_enabled argument specifies that we should ignore
* whether VFP is enabled via FPEXC[EN]: this should be true for FMXR/FMRX
* accesses to FPSID, FPEXC, MVFR0, MVFR1, MVFR2, and false for all other insns.
*/ */
static bool full_vfp_access_check(DisasContext *s, bool ignore_vfp_enabled) static void gen_update_fp_context(DisasContext *s)
{ {
if (s->fp_excp_el) {
if (arm_dc_feature(s, ARM_FEATURE_M)) {
/*
* M-profile mostly catches the "FPU disabled" case early, in
* disas_m_nocp(), but a few insns (eg LCTP, WLSTP, DLSTP)
* which do coprocessor-checks are outside the large ranges of
* the encoding space handled by the patterns in m-nocp.decode,
* and for them we may need to raise NOCP here.
*/
gen_exception_insn(s, s->pc_curr, EXCP_NOCP,
syn_uncategorized(), s->fp_excp_el);
} else {
gen_exception_insn(s, s->pc_curr, EXCP_UDEF,
syn_fp_access_trap(1, 0xe, false),
s->fp_excp_el);
}
return false;
}
if (!s->vfp_enabled && !ignore_vfp_enabled) {
assert(!arm_dc_feature(s, ARM_FEATURE_M));
unallocated_encoding(s);
return false;
}
if (arm_dc_feature(s, ARM_FEATURE_M)) {
/* Handle M-profile lazy FP state mechanics */
/* Trigger lazy-state preservation if necessary */
gen_preserve_fp_state(s);
/* Update ownership of FP context: set FPCCR.S to match current state */ /* Update ownership of FP context: set FPCCR.S to match current state */
if (s->v8m_fpccr_s_wrong) { if (s->v8m_fpccr_s_wrong) {
TCGv_i32 tmp; TCGv_i32 tmp;
@ -221,6 +187,52 @@ static bool full_vfp_access_check(DisasContext *s, bool ignore_vfp_enabled)
} }
} }
/*
* Check that VFP access is enabled. If it is, do the necessary
* M-profile lazy-FP handling and then return true.
* If not, emit code to generate an appropriate exception and
* return false.
* The ignore_vfp_enabled argument specifies that we should ignore
* whether VFP is enabled via FPEXC[EN]: this should be true for FMXR/FMRX
* accesses to FPSID, FPEXC, MVFR0, MVFR1, MVFR2, and false for all other insns.
*/
static bool full_vfp_access_check(DisasContext *s, bool ignore_vfp_enabled)
{
if (s->fp_excp_el) {
if (arm_dc_feature(s, ARM_FEATURE_M)) {
/*
* M-profile mostly catches the "FPU disabled" case early, in
* disas_m_nocp(), but a few insns (eg LCTP, WLSTP, DLSTP)
* which do coprocessor-checks are outside the large ranges of
* the encoding space handled by the patterns in m-nocp.decode,
* and for them we may need to raise NOCP here.
*/
gen_exception_insn(s, s->pc_curr, EXCP_NOCP,
syn_uncategorized(), s->fp_excp_el);
} else {
gen_exception_insn(s, s->pc_curr, EXCP_UDEF,
syn_fp_access_trap(1, 0xe, false),
s->fp_excp_el);
}
return false;
}
if (!s->vfp_enabled && !ignore_vfp_enabled) {
assert(!arm_dc_feature(s, ARM_FEATURE_M));
unallocated_encoding(s);
return false;
}
if (arm_dc_feature(s, ARM_FEATURE_M)) {
/* Handle M-profile lazy FP state mechanics */
/* Trigger lazy-state preservation if necessary */
gen_preserve_fp_state(s);
/* Update ownership of FP context and create new FP context if needed */
gen_update_fp_context(s);
}
return true; return true;
} }