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target/arm: Handle FPU check for FPCXT_NS insns via vfp_access_check_m()

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Instead of open-coding the "take NOCP exception if FPU disabled,
otherwise call gen_preserve_fp_state()" code in the accessors for
FPCXT_NS, add an argument to vfp_access_check_m() which tells it to
skip the gen_update_fp_context() call, so we can use it for the
FPCXT_NS case.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210618141019.10671-8-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2021-06-18 15:10:19 +01:00
parent e8cedaf779
commit 88137f787f
3 changed files with 11 additions and 14 deletions
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2
target/arm/translate-a32.h
View File

@ -32,7 +32,7 @@ bool disas_neon_shared(DisasContext *s, uint32_t insn);
void load_reg_var(DisasContext *s, TCGv_i32 var, int reg);
void arm_gen_condlabel(DisasContext *s);
bool vfp_access_check(DisasContext *s);
void gen_preserve_fp_state(DisasContext *s);
bool vfp_access_check_m(DisasContext *s, bool skip_context_update);
void read_neon_element32(TCGv_i32 dest, int reg, int ele, MemOp memop);
void read_neon_element64(TCGv_i64 dest, int reg, int ele, MemOp memop);
void write_neon_element32(TCGv_i32 src, int reg, int ele, MemOp memop);

10
target/arm/translate-m-nocp.c
View File

@ -371,9 +371,7 @@ static bool gen_M_fp_sysreg_write(DisasContext *s, int regno,
* otherwise PreserveFPState(), and then FPCXT_NS writes
* behave the same as FPCXT_S writes.
*/
if (s->fp_excp_el) {
gen_exception_insn(s, s->pc_curr, EXCP_NOCP,
syn_uncategorized(), s->fp_excp_el);
if (!vfp_access_check_m(s, true)) {
/*
* This was only a conditional exception, so override
* gen_exception_insn()'s default to DISAS_NORETURN
@ -381,7 +379,6 @@ static bool gen_M_fp_sysreg_write(DisasContext *s, int regno,
s->base.is_jmp = DISAS_NEXT;
break;
}
gen_preserve_fp_state(s);
}
/* fall through */
case ARM_VFP_FPCXT_S:
@ -527,9 +524,7 @@ static bool gen_M_fp_sysreg_read(DisasContext *s, int regno,
* otherwise PreserveFPState(), and then FPCXT_NS
* reads the same as FPCXT_S.
*/
if (s->fp_excp_el) {
gen_exception_insn(s, s->pc_curr, EXCP_NOCP,
syn_uncategorized(), s->fp_excp_el);
if (!vfp_access_check_m(s, true)) {
/*
* This was only a conditional exception, so override
* gen_exception_insn()'s default to DISAS_NORETURN
@ -537,7 +532,6 @@ static bool gen_M_fp_sysreg_read(DisasContext *s, int regno,
s->base.is_jmp = DISAS_NEXT;
break;
}
gen_preserve_fp_state(s);
tmp = tcg_temp_new_i32();
sfpa = tcg_temp_new_i32();
fpscr = tcg_temp_new_i32();

13
target/arm/translate-vfp.c
View File

@ -109,7 +109,7 @@ static inline long vfp_f16_offset(unsigned reg, bool top)
* Generate code for M-profile lazy FP state preservation if needed;
* this corresponds to the pseudocode PreserveFPState() function.
*/
void gen_preserve_fp_state(DisasContext *s)
static void gen_preserve_fp_state(DisasContext *s)
{
if (s->v7m_lspact) {
/*
@ -218,8 +218,9 @@ static bool vfp_access_check_a(DisasContext *s, bool ignore_vfp_enabled)
* If VFP is enabled, do the necessary M-profile lazy-FP handling and then
* return true. If not, emit code to generate an appropriate exception and
* return false.
* skip_context_update is true to skip the "update FP context" part of this.
*/
static bool vfp_access_check_m(DisasContext *s)
bool vfp_access_check_m(DisasContext *s, bool skip_context_update)
{
if (s->fp_excp_el) {
/*
@ -239,8 +240,10 @@ static bool vfp_access_check_m(DisasContext *s)
/* 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);
if (!skip_context_update) {
/* Update ownership of FP context and create new FP context if needed */
gen_update_fp_context(s);
}
return true;
}
@ -252,7 +255,7 @@ static bool vfp_access_check_m(DisasContext *s)
bool vfp_access_check(DisasContext *s)
{
if (arm_dc_feature(s, ARM_FEATURE_M)) {
return vfp_access_check_m(s);
return vfp_access_check_m(s, false);
} else {
return vfp_access_check_a(s, false);
}