While these functions really do return a 32-bit value,
widening the return type means that we need do less
marshalling between TCG types.
Remove NeonGenNarrowEnvFn typedef; add NeonGenOne64OpEnvFn.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
target/arm/helper.h | 22 ++++++------
target/arm/tcg/translate.h | 2 +-
target/arm/tcg/neon_helper.c | 22 ++++++------
target/arm/tcg/translate-a64.c | 60 ++++++++++++++++++---------------
target/arm/tcg/translate-neon.c | 44 ++++++++++++------------
5 files changed, 77 insertions(+), 73 deletions(-)
diff --git a/target/arm/helper.h b/target/arm/helper.h
index b40589d329..58919b670e 100644
--- a/target/arm/helper.h
+++ b/target/arm/helper.h
@@ -375,17 +375,17 @@ DEF_HELPER_3(neon_qrdmulh_s32, i32, env, i32, i32)
DEF_HELPER_4(neon_qrdmlah_s32, i32, env, s32, s32, s32)
DEF_HELPER_4(neon_qrdmlsh_s32, i32, env, s32, s32, s32)
-DEF_HELPER_1(neon_narrow_u8, i32, i64)
-DEF_HELPER_1(neon_narrow_u16, i32, i64)
-DEF_HELPER_2(neon_unarrow_sat8, i32, env, i64)
-DEF_HELPER_2(neon_narrow_sat_u8, i32, env, i64)
-DEF_HELPER_2(neon_narrow_sat_s8, i32, env, i64)
-DEF_HELPER_2(neon_unarrow_sat16, i32, env, i64)
-DEF_HELPER_2(neon_narrow_sat_u16, i32, env, i64)
-DEF_HELPER_2(neon_narrow_sat_s16, i32, env, i64)
-DEF_HELPER_2(neon_unarrow_sat32, i32, env, i64)
-DEF_HELPER_2(neon_narrow_sat_u32, i32, env, i64)
-DEF_HELPER_2(neon_narrow_sat_s32, i32, env, i64)
+DEF_HELPER_1(neon_narrow_u8, i64, i64)
+DEF_HELPER_1(neon_narrow_u16, i64, i64)
+DEF_HELPER_2(neon_unarrow_sat8, i64, env, i64)
+DEF_HELPER_2(neon_narrow_sat_u8, i64, env, i64)
+DEF_HELPER_2(neon_narrow_sat_s8, i64, env, i64)
+DEF_HELPER_2(neon_unarrow_sat16, i64, env, i64)
+DEF_HELPER_2(neon_narrow_sat_u16, i64, env, i64)
+DEF_HELPER_2(neon_narrow_sat_s16, i64, env, i64)
+DEF_HELPER_2(neon_unarrow_sat32, i64, env, i64)
+DEF_HELPER_2(neon_narrow_sat_u32, i64, env, i64)
+DEF_HELPER_2(neon_narrow_sat_s32, i64, env, i64)
DEF_HELPER_1(neon_narrow_high_u8, i32, i64)
DEF_HELPER_1(neon_narrow_high_u16, i32, i64)
DEF_HELPER_1(neon_narrow_round_high_u8, i32, i64)
diff --git a/target/arm/tcg/translate.h b/target/arm/tcg/translate.h
index 7721c627e9..5a2e10d64d 100644
--- a/target/arm/tcg/translate.h
+++ b/target/arm/tcg/translate.h
@@ -605,13 +605,13 @@ typedef void NeonGenThreeOpEnvFn(TCGv_i32, TCGv_env, TCGv_i32,
typedef void NeonGenTwo64OpFn(TCGv_i64, TCGv_i64, TCGv_i64);
typedef void NeonGenTwo64OpEnvFn(TCGv_i64, TCGv_ptr, TCGv_i64, TCGv_i64);
typedef void NeonGenNarrowFn(TCGv_i32, TCGv_i64);
-typedef void NeonGenNarrowEnvFn(TCGv_i32, TCGv_ptr, TCGv_i64);
typedef void NeonGenWidenFn(TCGv_i64, TCGv_i32);
typedef void NeonGenTwoOpWidenFn(TCGv_i64, TCGv_i32, TCGv_i32);
typedef void NeonGenOneSingleOpFn(TCGv_i32, TCGv_i32, TCGv_ptr);
typedef void NeonGenTwoSingleOpFn(TCGv_i32, TCGv_i32, TCGv_i32, TCGv_ptr);
typedef void NeonGenTwoDoubleOpFn(TCGv_i64, TCGv_i64, TCGv_i64, TCGv_ptr);
typedef void NeonGenOne64OpFn(TCGv_i64, TCGv_i64);
+typedef void NeonGenOne64OpEnvFn(TCGv_i64, TCGv_env, TCGv_i64);
typedef void CryptoTwoOpFn(TCGv_ptr, TCGv_ptr);
typedef void CryptoThreeOpIntFn(TCGv_ptr, TCGv_ptr, TCGv_i32);
typedef void CryptoThreeOpFn(TCGv_ptr, TCGv_ptr, TCGv_ptr);
diff --git a/target/arm/tcg/neon_helper.c b/target/arm/tcg/neon_helper.c
index 739e16e441..632df84a91 100644
--- a/target/arm/tcg/neon_helper.c
+++ b/target/arm/tcg/neon_helper.c
@@ -598,13 +598,13 @@ NEON_VOP_ENV(qrdmulh_s32, neon_s32, 1)
#undef NEON_FN
#undef NEON_QDMULH32
-uint32_t HELPER(neon_narrow_u8)(uint64_t x)
+uint64_t HELPER(neon_narrow_u8)(uint64_t x)
{
return (x & 0xffu) | ((x >> 8) & 0xff00u) | ((x >> 16) & 0xff0000u)
| ((x >> 24) & 0xff000000u);
}
-uint32_t HELPER(neon_narrow_u16)(uint64_t x)
+uint64_t HELPER(neon_narrow_u16)(uint64_t x)
{
return (x & 0xffffu) | ((x >> 16) & 0xffff0000u);
}
@@ -635,7 +635,7 @@ uint32_t HELPER(neon_narrow_round_high_u16)(uint64_t x)
return ((x >> 16) & 0xffff) | ((x >> 32) & 0xffff0000);
}
-uint32_t HELPER(neon_unarrow_sat8)(CPUARMState *env, uint64_t x)
+uint64_t HELPER(neon_unarrow_sat8)(CPUARMState *env, uint64_t x)
{
uint16_t s;
uint8_t d;
@@ -662,7 +662,7 @@ uint32_t HELPER(neon_unarrow_sat8)(CPUARMState *env, uint64_t x)
return res;
}
-uint32_t HELPER(neon_narrow_sat_u8)(CPUARMState *env, uint64_t x)
+uint64_t HELPER(neon_narrow_sat_u8)(CPUARMState *env, uint64_t x)
{
uint16_t s;
uint8_t d;
@@ -685,7 +685,7 @@ uint32_t HELPER(neon_narrow_sat_u8)(CPUARMState *env, uint64_t x)
return res;
}
-uint32_t HELPER(neon_narrow_sat_s8)(CPUARMState *env, uint64_t x)
+uint64_t HELPER(neon_narrow_sat_s8)(CPUARMState *env, uint64_t x)
{
int16_t s;
uint8_t d;
@@ -708,7 +708,7 @@ uint32_t HELPER(neon_narrow_sat_s8)(CPUARMState *env, uint64_t x)
return res;
}
-uint32_t HELPER(neon_unarrow_sat16)(CPUARMState *env, uint64_t x)
+uint64_t HELPER(neon_unarrow_sat16)(CPUARMState *env, uint64_t x)
{
uint32_t high;
uint32_t low;
@@ -731,7 +731,7 @@ uint32_t HELPER(neon_unarrow_sat16)(CPUARMState *env, uint64_t x)
return low | (high << 16);
}
-uint32_t HELPER(neon_narrow_sat_u16)(CPUARMState *env, uint64_t x)
+uint64_t HELPER(neon_narrow_sat_u16)(CPUARMState *env, uint64_t x)
{
uint32_t high;
uint32_t low;
@@ -748,7 +748,7 @@ uint32_t HELPER(neon_narrow_sat_u16)(CPUARMState *env, uint64_t x)
return low | (high << 16);
}
-uint32_t HELPER(neon_narrow_sat_s16)(CPUARMState *env, uint64_t x)
+uint64_t HELPER(neon_narrow_sat_s16)(CPUARMState *env, uint64_t x)
{
int32_t low;
int32_t high;
@@ -765,7 +765,7 @@ uint32_t HELPER(neon_narrow_sat_s16)(CPUARMState *env, uint64_t x)
return (uint16_t)low | (high << 16);
}
-uint32_t HELPER(neon_unarrow_sat32)(CPUARMState *env, uint64_t x)
+uint64_t HELPER(neon_unarrow_sat32)(CPUARMState *env, uint64_t x)
{
if (x & 0x8000000000000000ull) {
SET_QC();
@@ -778,7 +778,7 @@ uint32_t HELPER(neon_unarrow_sat32)(CPUARMState *env, uint64_t x)
return x;
}
-uint32_t HELPER(neon_narrow_sat_u32)(CPUARMState *env, uint64_t x)
+uint64_t HELPER(neon_narrow_sat_u32)(CPUARMState *env, uint64_t x)
{
if (x > 0xffffffffu) {
SET_QC();
@@ -787,7 +787,7 @@ uint32_t HELPER(neon_narrow_sat_u32)(CPUARMState *env, uint64_t x)
return x;
}
-uint32_t HELPER(neon_narrow_sat_s32)(CPUARMState *env, uint64_t x)
+uint64_t HELPER(neon_narrow_sat_s32)(CPUARMState *env, uint64_t x)
{
if ((int64_t)x != (int32_t)x) {
SET_QC();
diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 934746d2f2..7918720d9b 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -9439,11 +9439,9 @@ static void handle_vec_simd_sqshrn(DisasContext *s, bool is_scalar, bool is_q,
int elements = is_scalar ? 1 : (64 / esize);
bool round = extract32(opcode, 0, 1);
MemOp ldop = (size + 1) | (is_u_shift ? 0 : MO_SIGN);
- TCGv_i64 tcg_rn, tcg_rd;
- TCGv_i32 tcg_rd_narrowed;
- TCGv_i64 tcg_final;
+ TCGv_i64 tcg_rn, tcg_rd, tcg_final;
- static NeonGenNarrowEnvFn * const signed_narrow_fns[4][2] = {
+ static NeonGenOne64OpEnvFn * const signed_narrow_fns[4][2] = {
{ gen_helper_neon_narrow_sat_s8,
gen_helper_neon_unarrow_sat8 },
{ gen_helper_neon_narrow_sat_s16,
@@ -9452,13 +9450,13 @@ static void handle_vec_simd_sqshrn(DisasContext *s, bool is_scalar, bool is_q,
gen_helper_neon_unarrow_sat32 },
{ NULL, NULL },
};
- static NeonGenNarrowEnvFn * const unsigned_narrow_fns[4] = {
+ static NeonGenOne64OpEnvFn * const unsigned_narrow_fns[4] = {
gen_helper_neon_narrow_sat_u8,
gen_helper_neon_narrow_sat_u16,
gen_helper_neon_narrow_sat_u32,
NULL
};
- NeonGenNarrowEnvFn *narrowfn;
+ NeonGenOne64OpEnvFn *narrowfn;
int i;
@@ -9481,15 +9479,13 @@ static void handle_vec_simd_sqshrn(DisasContext *s, bool is_scalar, bool is_q,
tcg_rn = tcg_temp_new_i64();
tcg_rd = tcg_temp_new_i64();
- tcg_rd_narrowed = tcg_temp_new_i32();
tcg_final = tcg_temp_new_i64();
for (i = 0; i < elements; i++) {
read_vec_element(s, tcg_rn, rn, i, ldop);
handle_shri_with_rndacc(tcg_rd, tcg_rn, round,
false, is_u_shift, size+1, shift);
- narrowfn(tcg_rd_narrowed, tcg_env, tcg_rd);
- tcg_gen_extu_i32_i64(tcg_rd, tcg_rd_narrowed);
+ narrowfn(tcg_rd, tcg_env, tcg_rd);
if (i == 0) {
tcg_gen_extract_i64(tcg_final, tcg_rd, 0, esize);
} else {
@@ -10228,35 +10224,35 @@ static void handle_2misc_narrow(DisasContext *s, bool scalar,
* in the source becomes a size element in the destination).
*/
int pass;
- TCGv_i32 tcg_res[2];
+ TCGv_i64 tcg_res[2];
int destelt = is_q ? 2 : 0;
int passes = scalar ? 1 : 2;
if (scalar) {
- tcg_res[1] = tcg_constant_i32(0);
+ tcg_res[1] = tcg_constant_i64(0);
}
for (pass = 0; pass < passes; pass++) {
TCGv_i64 tcg_op = tcg_temp_new_i64();
- NeonGenNarrowFn *genfn = NULL;
- NeonGenNarrowEnvFn *genenvfn = NULL;
+ NeonGenOne64OpFn *genfn = NULL;
+ NeonGenOne64OpEnvFn *genenvfn = NULL;
if (scalar) {
read_vec_element(s, tcg_op, rn, pass, size + 1);
} else {
read_vec_element(s, tcg_op, rn, pass, MO_64);
}
- tcg_res[pass] = tcg_temp_new_i32();
+ tcg_res[pass] = tcg_temp_new_i64();
switch (opcode) {
case 0x12: /* XTN, SQXTUN */
{
- static NeonGenNarrowFn * const xtnfns[3] = {
+ static NeonGenOne64OpFn * const xtnfns[3] = {
gen_helper_neon_narrow_u8,
gen_helper_neon_narrow_u16,
- tcg_gen_extrl_i64_i32,
+ tcg_gen_ext32u_i64,
};
- static NeonGenNarrowEnvFn * const sqxtunfns[3] = {
+ static NeonGenOne64OpEnvFn * const sqxtunfns[3] = {
gen_helper_neon_unarrow_sat8,
gen_helper_neon_unarrow_sat16,
gen_helper_neon_unarrow_sat32,
@@ -10270,7 +10266,7 @@ static void handle_2misc_narrow(DisasContext *s, bool scalar,
}
case 0x14: /* SQXTN, UQXTN */
{
- static NeonGenNarrowEnvFn * const fns[3][2] = {
+ static NeonGenOne64OpEnvFn * const fns[3][2] = {
{ gen_helper_neon_narrow_sat_s8,
gen_helper_neon_narrow_sat_u8 },
{ gen_helper_neon_narrow_sat_s16,
@@ -10284,7 +10280,9 @@ static void handle_2misc_narrow(DisasContext *s, bool scalar,
case 0x16: /* FCVTN, FCVTN2 */
/* 32 bit to 16 bit or 64 bit to 32 bit float conversion */
if (size == 2) {
- gen_helper_vfp_fcvtsd(tcg_res[pass], tcg_op, tcg_env);
+ TCGv_i32 tmp = tcg_temp_new_i32();
+ gen_helper_vfp_fcvtsd(tmp, tcg_op, tcg_env);
+ tcg_gen_extu_i32_i64(tcg_res[pass], tmp);
} else {
TCGv_i32 tcg_lo = tcg_temp_new_i32();
TCGv_i32 tcg_hi = tcg_temp_new_i32();
@@ -10294,21 +10292,29 @@ static void handle_2misc_narrow(DisasContext *s, bool scalar,
tcg_gen_extr_i64_i32(tcg_lo, tcg_hi, tcg_op);
gen_helper_vfp_fcvt_f32_to_f16(tcg_lo, tcg_lo, fpst, ahp);
gen_helper_vfp_fcvt_f32_to_f16(tcg_hi, tcg_hi, fpst, ahp);
- tcg_gen_deposit_i32(tcg_res[pass], tcg_lo, tcg_hi, 16, 16);
+ tcg_gen_deposit_i32(tcg_lo, tcg_lo, tcg_hi, 16, 16);
+ tcg_gen_extu_i32_i64(tcg_res[pass], tcg_lo);
}
break;
case 0x36: /* BFCVTN, BFCVTN2 */
{
TCGv_ptr fpst = fpstatus_ptr(FPST_FPCR);
- gen_helper_bfcvt_pair(tcg_res[pass], tcg_op, fpst);
+ TCGv_i32 tmp = tcg_temp_new_i32();
+ gen_helper_bfcvt_pair(tmp, tcg_op, fpst);
+ tcg_gen_extu_i32_i64(tcg_res[pass], tmp);
}
break;
case 0x56: /* FCVTXN, FCVTXN2 */
- /* 64 bit to 32 bit float conversion
- * with von Neumann rounding (round to odd)
- */
- assert(size == 2);
- gen_helper_fcvtx_f64_to_f32(tcg_res[pass], tcg_op, tcg_env);
+ {
+ /*
+ * 64 bit to 32 bit float conversion
+ * with von Neumann rounding (round to odd)
+ */
+ TCGv_i32 tmp = tcg_temp_new_i32();
+ assert(size == 2);
+ gen_helper_fcvtx_f64_to_f32(tmp, tcg_op, tcg_env);
+ tcg_gen_extu_i32_i64(tcg_res[pass], tmp);
+ }
break;
default:
g_assert_not_reached();
@@ -10322,7 +10328,7 @@ static void handle_2misc_narrow(DisasContext *s, bool scalar,
}
for (pass = 0; pass < 2; pass++) {
- write_vec_element_i32(s, tcg_res[pass], rd, destelt + pass, MO_32);
+ write_vec_element(s, tcg_res[pass], rd, destelt + pass, MO_32);
}
clear_vec_high(s, is_q, rd);
}
diff --git a/target/arm/tcg/translate-neon.c b/target/arm/tcg/translate-neon.c
index 6dd70d1c53..9c8829ad7d 100644
--- a/target/arm/tcg/translate-neon.c
+++ b/target/arm/tcg/translate-neon.c
@@ -1107,11 +1107,10 @@ DO_2SH(VQSHL_S, gen_neon_sqshli)
static bool do_2shift_narrow_64(DisasContext *s, arg_2reg_shift *a,
NeonGenTwo64OpFn *shiftfn,
- NeonGenNarrowEnvFn *narrowfn)
+ NeonGenOne64OpEnvFn *narrowfn)
{
/* 2-reg-and-shift narrowing-shift operations, size == 3 case */
- TCGv_i64 constimm, rm1, rm2;
- TCGv_i32 rd;
+ TCGv_i64 constimm, rm1, rm2, rd;
if (!arm_dc_feature(s, ARM_FEATURE_NEON)) {
return false;
@@ -1138,7 +1137,7 @@ static bool do_2shift_narrow_64(DisasContext *s, arg_2reg_shift *a,
constimm = tcg_constant_i64(-a->shift);
rm1 = tcg_temp_new_i64();
rm2 = tcg_temp_new_i64();
- rd = tcg_temp_new_i32();
+ rd = tcg_temp_new_i64();
/* Load both inputs first to avoid potential overwrite if rm == rd */
read_neon_element64(rm1, a->vm, 0, MO_64);
@@ -1146,18 +1145,18 @@ static bool do_2shift_narrow_64(DisasContext *s, arg_2reg_shift *a,
shiftfn(rm1, rm1, constimm);
narrowfn(rd, tcg_env, rm1);
- write_neon_element32(rd, a->vd, 0, MO_32);
+ write_neon_element64(rd, a->vd, 0, MO_32);
shiftfn(rm2, rm2, constimm);
narrowfn(rd, tcg_env, rm2);
- write_neon_element32(rd, a->vd, 1, MO_32);
+ write_neon_element64(rd, a->vd, 1, MO_32);
return true;
}
static bool do_2shift_narrow_32(DisasContext *s, arg_2reg_shift *a,
NeonGenTwoOpFn *shiftfn,
- NeonGenNarrowEnvFn *narrowfn)
+ NeonGenOne64OpEnvFn *narrowfn)
{
/* 2-reg-and-shift narrowing-shift operations, size < 3 case */
TCGv_i32 constimm, rm1, rm2, rm3, rm4;
@@ -1212,16 +1211,16 @@ static bool do_2shift_narrow_32(DisasContext *s, arg_2reg_shift *a,
tcg_gen_concat_i32_i64(rtmp, rm1, rm2);
- narrowfn(rm1, tcg_env, rtmp);
- write_neon_element32(rm1, a->vd, 0, MO_32);
+ narrowfn(rtmp, tcg_env, rtmp);
+ write_neon_element64(rtmp, a->vd, 0, MO_32);
shiftfn(rm3, rm3, constimm);
shiftfn(rm4, rm4, constimm);
tcg_gen_concat_i32_i64(rtmp, rm3, rm4);
- narrowfn(rm3, tcg_env, rtmp);
- write_neon_element32(rm3, a->vd, 1, MO_32);
+ narrowfn(rtmp, tcg_env, rtmp);
+ write_neon_element64(rtmp, a->vd, 1, MO_32);
return true;
}
@@ -1236,17 +1235,17 @@ static bool do_2shift_narrow_32(DisasContext *s, arg_2reg_shift *a,
return do_2shift_narrow_32(s, a, FUNC, NARROWFUNC); \
}
-static void gen_neon_narrow_u32(TCGv_i32 dest, TCGv_ptr env, TCGv_i64 src)
+static void gen_neon_narrow_u32(TCGv_i64 dest, TCGv_ptr env, TCGv_i64 src)
{
- tcg_gen_extrl_i64_i32(dest, src);
+ tcg_gen_ext32u_i64(dest, src);
}
-static void gen_neon_narrow_u16(TCGv_i32 dest, TCGv_ptr env, TCGv_i64 src)
+static void gen_neon_narrow_u16(TCGv_i64 dest, TCGv_ptr env, TCGv_i64 src)
{
gen_helper_neon_narrow_u16(dest, src);
}
-static void gen_neon_narrow_u8(TCGv_i32 dest, TCGv_ptr env, TCGv_i64 src)
+static void gen_neon_narrow_u8(TCGv_i64 dest, TCGv_ptr env, TCGv_i64 src)
{
gen_helper_neon_narrow_u8(dest, src);
}
@@ -2837,10 +2836,9 @@ static bool trans_VZIP(DisasContext *s, arg_2misc *a)
}
static bool do_vmovn(DisasContext *s, arg_2misc *a,
- NeonGenNarrowEnvFn *narrowfn)
+ NeonGenOne64OpEnvFn *narrowfn)
{
- TCGv_i64 rm;
- TCGv_i32 rd0, rd1;
+ TCGv_i64 rm, rd0, rd1;
if (!arm_dc_feature(s, ARM_FEATURE_NEON)) {
return false;
@@ -2865,22 +2863,22 @@ static bool do_vmovn(DisasContext *s, arg_2misc *a,
}
rm = tcg_temp_new_i64();
- rd0 = tcg_temp_new_i32();
- rd1 = tcg_temp_new_i32();
+ rd0 = tcg_temp_new_i64();
+ rd1 = tcg_temp_new_i64();
read_neon_element64(rm, a->vm, 0, MO_64);
narrowfn(rd0, tcg_env, rm);
read_neon_element64(rm, a->vm, 1, MO_64);
narrowfn(rd1, tcg_env, rm);
- write_neon_element32(rd0, a->vd, 0, MO_32);
- write_neon_element32(rd1, a->vd, 1, MO_32);
+ write_neon_element64(rd0, a->vd, 0, MO_32);
+ write_neon_element64(rd1, a->vd, 1, MO_32);
return true;
}
#define DO_VMOVN(INSN, FUNC) \
static bool trans_##INSN(DisasContext *s, arg_2misc *a) \
{ \
- static NeonGenNarrowEnvFn * const narrowfn[] = { \
+ static NeonGenOne64OpEnvFn * const narrowfn[] = { \
FUNC##8, \
FUNC##16, \
FUNC##32, \
--
2.43.0On Mon, 9 Sept 2024 at 17:25, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> While these functions really do return a 32-bit value,
> widening the return type means that we need do less
> marshalling between TCG types.
>
> Remove NeonGenNarrowEnvFn typedef; add NeonGenOne64OpEnvFn.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> --- a/target/arm/tcg/neon_helper.c
> +++ b/target/arm/tcg/neon_helper.c
> @@ -598,13 +598,13 @@ NEON_VOP_ENV(qrdmulh_s32, neon_s32, 1)
> #undef NEON_FN
> #undef NEON_QDMULH32
>
> -uint32_t HELPER(neon_narrow_u8)(uint64_t x)
> +uint64_t HELPER(neon_narrow_u8)(uint64_t x)
> {
> return (x & 0xffu) | ((x >> 8) & 0xff00u) | ((x >> 16) & 0xff0000u)
> | ((x >> 24) & 0xff000000u);
> }
For almost all of these helper functions where we change the return
type, we return the same value we used to return, but zero extended
from 32 to 64 bits.
> -uint32_t HELPER(neon_narrow_sat_s32)(CPUARMState *env, uint64_t x)
> +uint64_t HELPER(neon_narrow_sat_s32)(CPUARMState *env, uint64_t x)
> {
> if ((int64_t)x != (int32_t)x) {
> SET_QC();
But for this one we don't. e.g. if the input is 0xffff0000ffff0000
then the old output was 0x80000000 and the new output is
0xffffffff80000000.
Presumably we're effectively ignoring the high 32 bits in
the caller, but this seems inconsistent.
It might also be helpful to have a comment describing what
the semantics of the return value is for this class of helpers.
I suspect also that coverity may complain about the
return (uint16_t)low | (high << 16);
in neon_unarrow_sat16, neon_narrow_sat_u16 and neon_narrow_sat_s16,
which have the desired semantics but look suspiciously like
somebody forgot to do the shift of 'high' as a 64-bit shift.
I guess we could write them as
return deposit32(low, 16, 16, high);
or maybe
return (uint16_t)low | (uint32_t)(high << 16);
to avoid that.
thanks
-- PMM
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