[otbn] ISS testcase for BN.LID
This checks that BN.LID loads its data in the right format and also
checks masking and wrapping behaviour for the grd operand. The masking
and wrapping behaviour for grs1 is still in flux, so I'm leaving that
for now.
Signed-off-by: Rupert Swarbrick <rswarbrick@lowrisc.org>
diff --git a/hw/ip/otbn/dv/otbnsim/test/simple/bn.lid/bnlid.s b/hw/ip/otbn/dv/otbnsim/test/simple/bn.lid/bnlid.s
new file mode 100644
index 0000000..4bab3ee
--- /dev/null
+++ b/hw/ip/otbn/dv/otbnsim/test/simple/bn.lid/bnlid.s
@@ -0,0 +1,66 @@
+/* Copyright lowRISC contributors. */
+/* Licensed under the Apache License, Version 2.0, see LICENSE for details. */
+/* SPDX-License-Identifier: Apache-2.0 */
+
+ /*
+ Check that bn.lid (wide data loading) loads its data as a 256-bit
+ little-endian value.
+
+ This should load 0x1f1e...0100 (see comment in .data section) from address
+ 0x0 into w0.
+ */
+ bn.lid x0, 0(x0)
+
+ /*
+ Checks for increment behaviour. First, incrementing <grd>: set x2 to 1,
+ then load-with-increment (from address 0x20, to distinguish from the
+ previous load). We should have data from 0x20 in w1 and x2 should equal 2.
+ */
+ addi x2, x0, 1
+ bn.lid x2++, 32(x0)
+
+ /*
+ Check wrapping and incrementing on the grd side. Set x3 to 32+2 and load
+ with increment from address 0x40. We should get data from 0x40 in w2 and x3
+ should equal 3
+ */
+ addi x3, x0, 34
+ bn.lid x3++, 64(x0)
+
+ ecall
+
+
+.section .data
+ /*
+ Since each .word is a 32-bit value stored little-endian, this is 32 bytes
+ laid out in memory as 00, 01, 02, .., 1f. If loaded 256-bit little endian,
+ the result will be 0x1f1e1d...020100.
+ */
+ .word 0x03020100
+ .word 0x07060504
+ .word 0x0b0a0908
+ .word 0x0f0e0d0c
+ .word 0x13121110
+ .word 0x17161514
+ .word 0x1b1a1918
+ .word 0x1f1e1d1c
+ /* The following words are carry on the count, so the next is 0x3f3e...2120
+ etc. */
+ /* Address 0x20: */
+ .word 0x23222120
+ .word 0x27262524
+ .word 0x2b2a2928
+ .word 0x2f2e2d2c
+ .word 0x33323130
+ .word 0x37363534
+ .word 0x3b3a3938
+ .word 0x3f3e3d3c
+ /* Address 0x40: */
+ .word 0x43424140
+ .word 0x47464544
+ .word 0x4b4a4948
+ .word 0x4f4e4d4c
+ .word 0x53525150
+ .word 0x57565554
+ .word 0x5b5a5958
+ .word 0x5f5e5d5c
diff --git a/hw/ip/otbn/dv/otbnsim/test/simple/bn.lid/expected.txt b/hw/ip/otbn/dv/otbnsim/test/simple/bn.lid/expected.txt
new file mode 100644
index 0000000..b13ea1b
--- /dev/null
+++ b/hw/ip/otbn/dv/otbnsim/test/simple/bn.lid/expected.txt
@@ -0,0 +1,9 @@
+# Copyright lowRISC contributors.
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+
+w0 = 0x1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100
+w1 = 0x3f3e3d3c3b3a393837363534333231302f2e2d2c2b2a29282726252423222120
+w2 = 0x5f5e5d5c5b5a595857565554535251504f4e4d4c4b4a49484746454443424140
+x2 = 2
+x3 = 3
