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[Qemu-devel] [PATCH for-2.0 v2 2/2] target-arm: A64: Add saturating accu
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From: |
Peter Maydell |
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Subject: |
[Qemu-devel] [PATCH for-2.0 v2 2/2] target-arm: A64: Add saturating accumulate ops (USQADD/SUQADD) |
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Date: |
Tue, 18 Mar 2014 23:01:24 +0000 |
From: Alex Bennée <address@hidden>
Add the saturating accumulate operations USQADD and SUQADD
to the A64 instruction set. This completes coverage of A64 Neon.
These operations (which are unsigned + signed -> signed and
signed + unsigned -> unsigned) don't exist in the A32/T32
instruction set, so require a complete new set of helper functions.
Signed-off-by: Alex Bennée <address@hidden>
Signed-off-by: Peter Maydell <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
---
target-arm/helper.h | 20 ++++--
target-arm/neon_helper.c | 165 +++++++++++++++++++++++++++++++++++++++++++++
target-arm/translate-a64.c | 109 ++++++++++++++++++++++++++++--
3 files changed, 284 insertions(+), 10 deletions(-)
diff --git a/target-arm/helper.h b/target-arm/helper.h
index b006fd5..366c1b3 100644
--- a/target-arm/helper.h
+++ b/target-arm/helper.h
@@ -186,12 +186,20 @@ DEF_HELPER_FLAGS_2(rints, TCG_CALL_NO_RWG, f32, f32, ptr)
DEF_HELPER_FLAGS_2(rintd, TCG_CALL_NO_RWG, f64, f64, ptr)
/* neon_helper.c */
-DEF_HELPER_3(neon_qadd_u8, i32, env, i32, i32)
-DEF_HELPER_3(neon_qadd_s8, i32, env, i32, i32)
-DEF_HELPER_3(neon_qadd_u16, i32, env, i32, i32)
-DEF_HELPER_3(neon_qadd_s16, i32, env, i32, i32)
-DEF_HELPER_3(neon_qadd_u32, i32, env, i32, i32)
-DEF_HELPER_3(neon_qadd_s32, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_qadd_u8, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_qadd_s8, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_qadd_u16, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_qadd_s16, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_qadd_u32, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_qadd_s32, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_uqadd_s8, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_uqadd_s16, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_uqadd_s32, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_uqadd_s64, TCG_CALL_NO_RWG, i64, env, i64, i64)
+DEF_HELPER_FLAGS_3(neon_sqadd_u8, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_sqadd_u16, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_sqadd_u32, TCG_CALL_NO_RWG, i32, env, i32, i32)
+DEF_HELPER_FLAGS_3(neon_sqadd_u64, TCG_CALL_NO_RWG, i64, env, i64, i64)
DEF_HELPER_3(neon_qsub_u8, i32, env, i32, i32)
DEF_HELPER_3(neon_qsub_s8, i32, env, i32, i32)
DEF_HELPER_3(neon_qsub_u16, i32, env, i32, i32)
diff --git a/target-arm/neon_helper.c b/target-arm/neon_helper.c
index e23f224..8d6f9a9 100644
--- a/target-arm/neon_helper.c
+++ b/target-arm/neon_helper.c
@@ -236,6 +236,171 @@ uint64_t HELPER(neon_qadd_s64)(CPUARMState *env, uint64_t
src1, uint64_t src2)
return res;
}
+/* Unsigned saturating accumulate of signed value
+ *
+ * Op1/Rn is treated as signed
+ * Op2/Rd is treated as unsigned
+ *
+ * Explicit casting is used to ensure the correct sign extension of
+ * inputs. The result is treated as a unsigned value and saturated as such.
+ *
+ * We use a macro for the 8/16 bit cases which expects signed integers of va,
+ * vb, and vr for interim calculation and an unsigned 32 bit result value r.
+ */
+
+#define USATACC(bits, shift) \
+ do { \
+ va = sextract32(a, shift, bits); \
+ vb = extract32(b, shift, bits); \
+ vr = va + vb; \
+ if (vr > UINT##bits##_MAX) { \
+ SET_QC(); \
+ vr = UINT##bits##_MAX; \
+ } else if (vr < 0) { \
+ SET_QC(); \
+ vr = 0; \
+ } \
+ r = deposit32(r, shift, bits, vr); \
+ } while (0)
+
+uint32_t HELPER(neon_uqadd_s8)(CPUARMState *env, uint32_t a, uint32_t b)
+{
+ int16_t va, vb, vr;
+ uint32_t r = 0;
+
+ USATACC(8, 0);
+ USATACC(8, 8);
+ USATACC(8, 16);
+ USATACC(8, 24);
+ return r;
+}
+
+uint32_t HELPER(neon_uqadd_s16)(CPUARMState *env, uint32_t a, uint32_t b)
+{
+ int32_t va, vb, vr;
+ uint64_t r = 0;
+
+ USATACC(16, 0);
+ USATACC(16, 16);
+ return r;
+}
+
+#undef USATACC
+
+uint32_t HELPER(neon_uqadd_s32)(CPUARMState *env, uint32_t a, uint32_t b)
+{
+ int64_t va = (int32_t)a;
+ int64_t vb = (uint32_t)b;
+ int64_t vr = va + vb;
+ if (vr > UINT32_MAX) {
+ SET_QC();
+ vr = UINT32_MAX;
+ } else if (vr < 0) {
+ SET_QC();
+ vr = 0;
+ }
+ return vr;
+}
+
+uint64_t HELPER(neon_uqadd_s64)(CPUARMState *env, uint64_t a, uint64_t b)
+{
+ uint64_t res;
+ res = a + b;
+ /* We only need to look at the pattern of SIGN bits to detect
+ * +ve/-ve saturation
+ */
+ if (~a & b & ~res & SIGNBIT64) {
+ SET_QC();
+ res = UINT64_MAX;
+ } else if (a & ~b & res & SIGNBIT64) {
+ SET_QC();
+ res = 0;
+ }
+ return res;
+}
+
+/* Signed saturating accumulate of unsigned value
+ *
+ * Op1/Rn is treated as unsigned
+ * Op2/Rd is treated as signed
+ *
+ * The result is treated as a signed value and saturated as such
+ *
+ * We use a macro for the 8/16 bit cases which expects signed integers of va,
+ * vb, and vr for interim calculation and an unsigned 32 bit result value r.
+ */
+
+#define SSATACC(bits, shift) \
+ do { \
+ va = extract32(a, shift, bits); \
+ vb = sextract32(b, shift, bits); \
+ vr = va + vb; \
+ if (vr > INT##bits##_MAX) { \
+ SET_QC(); \
+ vr = INT##bits##_MAX; \
+ } else if (vr < INT##bits##_MIN) { \
+ SET_QC(); \
+ vr = INT##bits##_MIN; \
+ } \
+ r = deposit32(r, shift, bits, vr); \
+ } while (0)
+
+uint32_t HELPER(neon_sqadd_u8)(CPUARMState *env, uint32_t a, uint32_t b)
+{
+ int16_t va, vb, vr;
+ uint32_t r = 0;
+
+ SSATACC(8, 0);
+ SSATACC(8, 8);
+ SSATACC(8, 16);
+ SSATACC(8, 24);
+ return r;
+}
+
+uint32_t HELPER(neon_sqadd_u16)(CPUARMState *env, uint32_t a, uint32_t b)
+{
+ int32_t va, vb, vr;
+ uint32_t r = 0;
+
+ SSATACC(16, 0);
+ SSATACC(16, 16);
+
+ return r;
+}
+
+#undef SSATACC
+
+uint32_t HELPER(neon_sqadd_u32)(CPUARMState *env, uint32_t a, uint32_t b)
+{
+ int64_t res;
+ int64_t op1 = (uint32_t)a;
+ int64_t op2 = (int32_t)b;
+ res = op1 + op2;
+ if (res > INT32_MAX) {
+ SET_QC();
+ res = INT32_MAX;
+ } else if (res < INT32_MIN) {
+ SET_QC();
+ res = INT32_MIN;
+ }
+ return res;
+}
+
+uint64_t HELPER(neon_sqadd_u64)(CPUARMState *env, uint64_t a, uint64_t b)
+{
+ uint64_t res;
+ res = a + b;
+ /* We only need to look at the pattern of SIGN bits to detect an overflow
*/
+ if (((a & res)
+ | (~b & res)
+ | (a & ~b)) & SIGNBIT64) {
+ SET_QC();
+ res = INT64_MAX;
+ }
+ return res;
+}
+
+
#define NEON_USAT(dest, src1, src2, type) do { \
uint32_t tmp = (uint32_t)src1 - (uint32_t)src2; \
if (tmp != (type)tmp) { \
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index 18659d7..9f06450 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -7321,6 +7321,101 @@ static void handle_2misc_narrow(DisasContext *s, bool
scalar,
}
}
+/* Remaining saturating accumulating ops */
+static void handle_2misc_satacc(DisasContext *s, bool is_scalar, bool is_u,
+ bool is_q, int size, int rn, int rd)
+{
+ bool is_double = (size == 3);
+
+ if (is_double) {
+ TCGv_i64 tcg_rn = tcg_temp_new_i64();
+ TCGv_i64 tcg_rd = tcg_temp_new_i64();
+ int pass;
+
+ for (pass = 0; pass < (is_scalar ? 1 : 2); pass++) {
+ read_vec_element(s, tcg_rn, rn, pass, MO_64);
+ read_vec_element(s, tcg_rd, rd, pass, MO_64);
+
+ if (is_u) { /* USQADD */
+ gen_helper_neon_uqadd_s64(tcg_rd, cpu_env, tcg_rn, tcg_rd);
+ } else { /* SUQADD */
+ gen_helper_neon_sqadd_u64(tcg_rd, cpu_env, tcg_rn, tcg_rd);
+ }
+ write_vec_element(s, tcg_rd, rd, pass, MO_64);
+ }
+ if (is_scalar) {
+ clear_vec_high(s, rd);
+ }
+
+ tcg_temp_free_i64(tcg_rd);
+ tcg_temp_free_i64(tcg_rn);
+ } else {
+ TCGv_i32 tcg_rn = tcg_temp_new_i32();
+ TCGv_i32 tcg_rd = tcg_temp_new_i32();
+ int pass, maxpasses;
+
+ if (is_scalar) {
+ maxpasses = 1;
+ } else {
+ maxpasses = is_q ? 4 : 2;
+ }
+
+ for (pass = 0; pass < maxpasses; pass++) {
+ if (is_scalar) {
+ read_vec_element_i32(s, tcg_rn, rn, pass, size);
+ read_vec_element_i32(s, tcg_rd, rd, pass, size);
+ } else {
+ read_vec_element_i32(s, tcg_rn, rn, pass, MO_32);
+ read_vec_element_i32(s, tcg_rd, rd, pass, MO_32);
+ }
+
+ if (is_u) { /* USQADD */
+ switch (size) {
+ case 0:
+ gen_helper_neon_uqadd_s8(tcg_rd, cpu_env, tcg_rn, tcg_rd);
+ break;
+ case 1:
+ gen_helper_neon_uqadd_s16(tcg_rd, cpu_env, tcg_rn, tcg_rd);
+ break;
+ case 2:
+ gen_helper_neon_uqadd_s32(tcg_rd, cpu_env, tcg_rn, tcg_rd);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+ } else { /* SUQADD */
+ switch (size) {
+ case 0:
+ gen_helper_neon_sqadd_u8(tcg_rd, cpu_env, tcg_rn, tcg_rd);
+ break;
+ case 1:
+ gen_helper_neon_sqadd_u16(tcg_rd, cpu_env, tcg_rn, tcg_rd);
+ break;
+ case 2:
+ gen_helper_neon_sqadd_u32(tcg_rd, cpu_env, tcg_rn, tcg_rd);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+ }
+
+ if (is_scalar) {
+ TCGv_i64 tcg_zero = tcg_const_i64(0);
+ write_vec_element(s, tcg_zero, rd, 0, MO_64);
+ tcg_temp_free_i64(tcg_zero);
+ }
+ write_vec_element_i32(s, tcg_rd, rd, pass, MO_32);
+ }
+
+ if (!is_q) {
+ clear_vec_high(s, rd);
+ }
+
+ tcg_temp_free_i32(tcg_rd);
+ tcg_temp_free_i32(tcg_rn);
+ }
+}
+
/* C3.6.12 AdvSIMD scalar two reg misc
* 31 30 29 28 24 23 22 21 17 16 12 11 10 9 5 4 0
* +-----+---+-----------+------+-----------+--------+-----+------+------+
@@ -7340,6 +7435,9 @@ static void disas_simd_scalar_two_reg_misc(DisasContext
*s, uint32_t insn)
TCGv_ptr tcg_fpstatus;
switch (opcode) {
+ case 0x3: /* USQADD / SUQADD*/
+ handle_2misc_satacc(s, true, u, false, size, rn, rd);
+ return;
case 0x7: /* SQABS / SQNEG */
break;
case 0xa: /* CMLT */
@@ -7427,10 +7525,7 @@ static void disas_simd_scalar_two_reg_misc(DisasContext
*s, uint32_t insn)
}
break;
default:
- /* Other categories of encoding in this class:
- * + SUQADD/USQADD/SQABS/SQNEG : size 8, 16, 32 or 64
- */
- unsupported_encoding(s, insn);
+ unallocated_encoding(s);
return;
}
@@ -9194,6 +9289,12 @@ static void disas_simd_two_reg_misc(DisasContext *s,
uint32_t insn)
}
break;
case 0x3: /* SUQADD, USQADD */
+ if (size == 3 && !is_q) {
+ unallocated_encoding(s);
+ return;
+ }
+ handle_2misc_satacc(s, false, u, is_q, size, rn, rd);
+ return;
case 0x7: /* SQABS, SQNEG */
if (size == 3 && !is_q) {
unallocated_encoding(s);
--
1.9.0