target/arm: Simplify do_reduction_op
Use simple shift and add instead of ctpop, ctz, shift and mask.
Unlike SVE, there is no predicate to disable elements.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240912024114.1097832-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 04160b2..74efb35 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -9027,34 +9027,23 @@
* important for correct NaN propagation that we do these
* operations in exactly the order specified by the pseudocode.
*
- * This is a recursive function, TCG temps should be freed by the
- * calling function once it is done with the values.
+ * This is a recursive function.
*/
static TCGv_i32 do_reduction_op(DisasContext *s, int fpopcode, int rn,
- int esize, int size, int vmap, TCGv_ptr fpst)
+ MemOp esz, int ebase, int ecount, TCGv_ptr fpst)
{
- if (esize == size) {
- int element;
- MemOp msize = esize == 16 ? MO_16 : MO_32;
- TCGv_i32 tcg_elem;
-
- /* We should have one register left here */
- assert(ctpop8(vmap) == 1);
- element = ctz32(vmap);
- assert(element < 8);
-
- tcg_elem = tcg_temp_new_i32();
- read_vec_element_i32(s, tcg_elem, rn, element, msize);
+ if (ecount == 1) {
+ TCGv_i32 tcg_elem = tcg_temp_new_i32();
+ read_vec_element_i32(s, tcg_elem, rn, ebase, esz);
return tcg_elem;
} else {
- int bits = size / 2;
- int shift = ctpop8(vmap) / 2;
- int vmap_lo = (vmap >> shift) & vmap;
- int vmap_hi = (vmap & ~vmap_lo);
+ int half = ecount >> 1;
TCGv_i32 tcg_hi, tcg_lo, tcg_res;
- tcg_hi = do_reduction_op(s, fpopcode, rn, esize, bits, vmap_hi, fpst);
- tcg_lo = do_reduction_op(s, fpopcode, rn, esize, bits, vmap_lo, fpst);
+ tcg_hi = do_reduction_op(s, fpopcode, rn, esz,
+ ebase + half, half, fpst);
+ tcg_lo = do_reduction_op(s, fpopcode, rn, esz,
+ ebase, half, fpst);
tcg_res = tcg_temp_new_i32();
switch (fpopcode) {
@@ -9105,7 +9094,6 @@
bool is_u = extract32(insn, 29, 1);
bool is_fp = false;
bool is_min = false;
- int esize;
int elements;
int i;
TCGv_i64 tcg_res, tcg_elt;
@@ -9152,8 +9140,7 @@
return;
}
- esize = 8 << size;
- elements = (is_q ? 128 : 64) / esize;
+ elements = (is_q ? 16 : 8) >> size;
tcg_res = tcg_temp_new_i64();
tcg_elt = tcg_temp_new_i64();
@@ -9208,9 +9195,8 @@
*/
TCGv_ptr fpst = fpstatus_ptr(size == MO_16 ? FPST_FPCR_F16 : FPST_FPCR);
int fpopcode = opcode | is_min << 4 | is_u << 5;
- int vmap = (1 << elements) - 1;
- TCGv_i32 tcg_res32 = do_reduction_op(s, fpopcode, rn, esize,
- (is_q ? 128 : 64), vmap, fpst);
+ TCGv_i32 tcg_res32 = do_reduction_op(s, fpopcode, rn, size,
+ 0, elements, fpst);
tcg_gen_extu_i32_i64(tcg_res, tcg_res32);
}
