testsuite: aarch64: Add zero-high-half tests for narrowing shifts

Add tests to verify that Neon narrowing-shift instructions clear the
top half of the result vector. It is sufficient to show that a
subsequent combine with a zero-vector is optimized away - leaving
just the narrowing-shift instruction.

gcc/testsuite/ChangeLog:

2021-06-15  Jonathan Wright  <jonathan.wright@arm.com>

	* gcc.target/aarch64/narrow_zero_high_half.c: New test.

diff --git a/gcc/testsuite/gcc.target/aarch64/narrow_zero_high_half.c b/gcc/testsuite/gcc.target/aarch64/narrow_zero_high_half.c
new file mode 100644 (file)
index 0000000..a79a4c3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/narrow_zero_high_half.c
@@ -0,0 +1,60 @@
+/* { dg-skip-if "" { arm*-*-* } } */
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+#include <arm_neon.h>
+
+#define TEST_SHIFT(name, rettype, intype, fs, rs) \
+  rettype test_ ## name ## _ ## fs ## _zero_high \
+               (intype a) \
+       { \
+               return vcombine_ ## rs (name ## _ ## fs (a, 4), \
+                                       vdup_n_ ## rs (0)); \
+       }
+
+TEST_SHIFT (vshrn_n, int8x16_t, int16x8_t, s16, s8)
+TEST_SHIFT (vshrn_n, int16x8_t, int32x4_t, s32, s16)
+TEST_SHIFT (vshrn_n, int32x4_t, int64x2_t, s64, s32)
+TEST_SHIFT (vshrn_n, uint8x16_t, uint16x8_t, u16, u8)
+TEST_SHIFT (vshrn_n, uint16x8_t, uint32x4_t, u32, u16)
+TEST_SHIFT (vshrn_n, uint32x4_t, uint64x2_t, u64, u32)
+
+TEST_SHIFT (vrshrn_n, int8x16_t, int16x8_t, s16, s8)
+TEST_SHIFT (vrshrn_n, int16x8_t, int32x4_t, s32, s16)
+TEST_SHIFT (vrshrn_n, int32x4_t, int64x2_t, s64, s32)
+TEST_SHIFT (vrshrn_n, uint8x16_t, uint16x8_t, u16, u8)
+TEST_SHIFT (vrshrn_n, uint16x8_t, uint32x4_t, u32, u16)
+TEST_SHIFT (vrshrn_n, uint32x4_t, uint64x2_t, u64, u32)
+
+TEST_SHIFT (vqshrn_n, int8x16_t, int16x8_t, s16, s8)
+TEST_SHIFT (vqshrn_n, int16x8_t, int32x4_t, s32, s16)
+TEST_SHIFT (vqshrn_n, int32x4_t, int64x2_t, s64, s32)
+TEST_SHIFT (vqshrn_n, uint8x16_t, uint16x8_t, u16, u8)
+TEST_SHIFT (vqshrn_n, uint16x8_t, uint32x4_t, u32, u16)
+TEST_SHIFT (vqshrn_n, uint32x4_t, uint64x2_t, u64, u32)
+
+TEST_SHIFT (vqrshrn_n, int8x16_t, int16x8_t, s16, s8)
+TEST_SHIFT (vqrshrn_n, int16x8_t, int32x4_t, s32, s16)
+TEST_SHIFT (vqrshrn_n, int32x4_t, int64x2_t, s64, s32)
+TEST_SHIFT (vqrshrn_n, uint8x16_t, uint16x8_t, u16, u8)
+TEST_SHIFT (vqrshrn_n, uint16x8_t, uint32x4_t, u32, u16)
+TEST_SHIFT (vqrshrn_n, uint32x4_t, uint64x2_t, u64, u32)
+
+TEST_SHIFT (vqshrun_n, uint8x16_t, int16x8_t, s16, u8)
+TEST_SHIFT (vqshrun_n, uint16x8_t, int32x4_t, s32, u16)
+TEST_SHIFT (vqshrun_n, uint32x4_t, int64x2_t, s64, u32)
+
+TEST_SHIFT (vqrshrun_n, uint8x16_t, int16x8_t, s16, u8)
+TEST_SHIFT (vqrshrun_n, uint16x8_t, int32x4_t, s32, u16)
+TEST_SHIFT (vqrshrun_n, uint32x4_t, int64x2_t, s64, u32)
+
+/* { dg-final { scan-assembler-not "dup\\t" } } */
+
+/* { dg-final { scan-assembler-times "\\tshrn\\tv" 6} }  */
+/* { dg-final { scan-assembler-times "\\trshrn\\tv" 6} }  */
+/* { dg-final { scan-assembler-times "\\tsqshrn\\tv" 3} }  */
+/* { dg-final { scan-assembler-times "\\tuqshrn\\tv" 3} }  */
+/* { dg-final { scan-assembler-times "\\tsqrshrn\\tv" 3} }  */
+/* { dg-final { scan-assembler-times "\\tuqrshrn\\tv" 3} }  */
+/* { dg-final { scan-assembler-times "\\tsqshrun\\tv" 3} }  */
+/* { dg-final { scan-assembler-times "\\tsqrshrun\\tv" 3} }  */