target/arm: Implement MVE VSHLL
Implement the MVE VHLL (vector shift left long) insn. This has two
encodings: the T1 encoding is the usual shift-by-immediate format,
and the T2 encoding is a special case where the shift count is always
equal to the element size.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210628135835.6690-10-peter.maydell@linaro.org
diff --git a/target/arm/mve_helper.c b/target/arm/mve_helper.c
index ac720c9..8798e77 100644
--- a/target/arm/mve_helper.c
+++ b/target/arm/mve_helper.c
@@ -1250,3 +1250,35 @@
DO_2SHIFT_SAT_S(vqshlui_s, DO_SUQSHL_OP)
DO_2SHIFT_U(vrshli_u, DO_VRSHLU)
DO_2SHIFT_S(vrshli_s, DO_VRSHLS)
+
+/*
+ * Long shifts taking half-sized inputs from top or bottom of the input
+ * vector and producing a double-width result. ESIZE, TYPE are for
+ * the input, and LESIZE, LTYPE for the output.
+ * Unlike the normal shift helpers, we do not handle negative shift counts,
+ * because the long shift is strictly left-only.
+ */
+#define DO_VSHLL(OP, TOP, ESIZE, TYPE, LESIZE, LTYPE) \
+ void HELPER(glue(mve_, OP))(CPUARMState *env, void *vd, \
+ void *vm, uint32_t shift) \
+ { \
+ LTYPE *d = vd; \
+ TYPE *m = vm; \
+ uint16_t mask = mve_element_mask(env); \
+ unsigned le; \
+ assert(shift <= 16); \
+ for (le = 0; le < 16 / LESIZE; le++, mask >>= LESIZE) { \
+ LTYPE r = (LTYPE)m[H##ESIZE(le * 2 + TOP)] << shift; \
+ mergemask(&d[H##LESIZE(le)], r, mask); \
+ } \
+ mve_advance_vpt(env); \
+ }
+
+#define DO_VSHLL_ALL(OP, TOP) \
+ DO_VSHLL(OP##sb, TOP, 1, int8_t, 2, int16_t) \
+ DO_VSHLL(OP##ub, TOP, 1, uint8_t, 2, uint16_t) \
+ DO_VSHLL(OP##sh, TOP, 2, int16_t, 4, int32_t) \
+ DO_VSHLL(OP##uh, TOP, 2, uint16_t, 4, uint32_t) \
+
+DO_VSHLL_ALL(vshllb, false)
+DO_VSHLL_ALL(vshllt, true)
