For "sub", compute carry by comparing inputs.

Test.

diff --git a/sim/testsuite/d10v-elf/.Sanitize b/sim/testsuite/d10v-elf/.Sanitize
index 5ca3dd479a0f61cfdab39899cc675073d1f5943c..2f3a8d8d1699a56c2d4e70a7c2ef5587e52933ec 100644 (file)
--- a/sim/testsuite/d10v-elf/.Sanitize
+++ b/sim/testsuite/d10v-elf/.Sanitize
@@ -15,6 +15,7 @@ t-msbu.s
 t-rachi.s
 t-rep.s
 t-mulxu.s
+t-sub.s
 t-subi.s
 t-sub2w.s
 t-mvtac.s

diff --git a/sim/testsuite/d10v-elf/t-sub.s b/sim/testsuite/d10v-elf/t-sub.s
new file mode 100644 (file)
index 0000000..26d0a3a
--- /dev/null
+++ b/sim/testsuite/d10v-elf/t-sub.s
@@ -0,0 +1,42 @@
+.include "t-macros.i"
+
+       start
+
+;;  The d10v implements negated addition for subtraction
+
+       .macro check_sub s x y r c
+       ;; clear carry
+       ldi     r6,#0x8004
+       mvtc    r6,cr0
+       ;; subtract
+       ldi     r10,#\x
+       ldi     r11,#\y
+       sub     r10, r11
+       ;; verify result
+       ldi     r12, #\r
+       cmpeq   r10, r12
+       brf0t   1f
+       ldi     r6, 1
+       ldi     r2, #\s
+       trap    15
+1:
+       ;; verify carry
+       mvfc    r6, cr0
+       and3    r6, r6, #1
+       cmpeqi  r6, #\c
+       brf0t   1f
+       ldi     r6, 1
+       ldi     r2, #\s
+       trap    15
+1:
+       .endm
+
+check_sub 1 0x0000 0x0000  0x0000  1
+check_sub 2 0x0000 0x0001  0xffff  0
+check_sub 3 0x0001 0x0000  0x0001  1
+check_sub 4 0x0001 0x0001  0x0000  1
+check_sub 5 0x0000 0x8000  0x8000  0
+check_sub 6 0x8000 0x0001  0x7fff  1
+check_sub 7 0x7fff 0x7fff  0x0000  1
+
+       exit0