The attached patches add an "-mnodiv" option to FT32, preventing use of the
divide and modulo instructions. This required additional software div/mod
implemtations in FT32's libgcc.
2016-03-28 James Bowman <james.bow...@ftdichip.com>
* config/ft32/ft32.opt (mnodiv): New.
* config/ft32/ft32.md (*divsi3, *modsi3): Qualify with
TARGET_NODIV.
* doc/invoke.texi (FT32 Options -mnodiv): New.
2016-03-28 James Bowman <james.bow...@ftdichip.com>
* libgcc/config/ft32/lib1funcs.S (*divsi3, *modsi3): New.
Index: gcc/config/ft32/ft32.md
===================================================================
--- gcc/config/ft32/ft32.md (revision 234405)
+++ gcc/config/ft32/ft32.md (working copy)
@@ -101,7 +101,7 @@
(div:SI
(match_operand:SI 1 "register_operand" "r,r")
(match_operand:SI 2 "ft32_rimm_operand" "r,KA")))]
- ""
+ "!TARGET_NODIV"
"div.l %0,%1,%2")
(define_insn "modsi3"
@@ -109,7 +109,7 @@
(mod:SI
(match_operand:SI 1 "register_operand" "r,r")
(match_operand:SI 2 "ft32_rimm_operand" "r,KA")))]
- ""
+ "!TARGET_NODIV"
"mod.l %0,%1,%2")
(define_insn "udivsi3"
@@ -117,7 +117,7 @@
(udiv:SI
(match_operand:SI 1 "register_operand" "r,r")
(match_operand:SI 2 "ft32_rimm_operand" "r,KA")))]
- ""
+ "!TARGET_NODIV"
"udiv.l %0,%1,%2")
(define_insn "umodsi3"
@@ -125,7 +125,7 @@
(umod:SI
(match_operand:SI 1 "register_operand" "r,r")
(match_operand:SI 2 "register_operand" "r,KA")))]
- ""
+ "!TARGET_NODIV"
"umod.l %0,%1,%2")
(define_insn "extvsi"
Index: gcc/config/ft32/ft32.opt
===================================================================
--- gcc/config/ft32/ft32.opt (revision 234405)
+++ gcc/config/ft32/ft32.opt (working copy)
@@ -25,3 +25,7 @@ target the software simulator.
mlra
Target Report Var(ft32_lra_flag) Init(0) Save
Use LRA instead of reload.
+
+mnodiv
+Target Report Mask(NODIV)
+Avoid use of the DIV and MOD instructions
Index: libgcc/config/ft32/lib1funcs.S
===================================================================
--- libgcc/config/ft32/lib1funcs.S (revision 234405)
+++ libgcc/config/ft32/lib1funcs.S (working copy)
@@ -25,8 +25,8 @@ see the files COPYING3 and COPYING.RUNTI
# for implementation details of all except division which is detailed below
#
+#ifdef L_fp_tools
// .global __cmpsf2_
-
nan: .long 0x7FFFFFFF # also abs mask
inf: .long 0x7F800000
sign_mask: .long 0x80000000
@@ -37,6 +37,14 @@ smallest_norm: .long 0x00800000 # im
high_FF: .long 0xFF000000
high_uint: .long 0xFFFFFFFF
+ntz_table:
+ .byte 32,0,1,12,2,6,0,13,3,0,7,0,0,0,0,14
+ .byte 10,4,0,0,8,0,0,25,0,0,0,0,0,21,27,15
+ .byte 31,11,5,0,0,0,0,0,9,0,0,24,0,0,20,26
+ .byte 30,0,0,0,0,23,0,19,29,0,22,18,28,17,16,0
+
+#endif
+
# Supply a few 'missing' instructions
# not
@@ -87,12 +95,6 @@ high_uint: .long 0xFFFFFFFF
lpmi.b \x, \x, 0
.endm
-ntz_table:
- .byte 32,0,1,12,2,6,0,13,3,0,7,0,0,0,0,14
- .byte 10,4,0,0,8,0,0,25,0,0,0,0,0,21,27,15
- .byte 31,11,5,0,0,0,0,0,9,0,0,24,0,0,20,26
- .byte 30,0,0,0,0,23,0,19,29,0,22,18,28,17,16,0
-
# calculate leading zero count
.macro nlz x, scr
flip \x, \x, 31
@@ -503,6 +505,9 @@ mul_z0:
## for implementation details
+
+
+#ifdef L_divsf3
dc_1: .long 0xffffe7d7
dc_2: .long 0xffffffe8
dc_3: .long 0xffbad86f
@@ -517,9 +522,6 @@ dc_11: .long 0x0452b1bf
dc_12: .long 0xFFFFFFC0
spec_val_test: .long 0x7F7FFFFF
-
-
-#ifdef L_divsf3
.global __divsf3
__divsf3:
push $r13
@@ -869,6 +871,7 @@ float_not_zero2:
return
#endif
+#if 0
##########################################################################
##########################################################################
## float compare
@@ -913,7 +916,74 @@ cmp_is_gt:
cmp_is_eq:
ldk $r0, 0
return
+#endif
+#ifdef L_udivsi3
+.global __udivsi3
+__udivsi3:
+ # $r0 is dividend
+ # $r1 is divisor
+ ldk $r2,0
+ push $r28
+ ldk $r28,-32
+0:
+ lshr $r3,$r0,31 # Shift $r2:$r0 left one
+ ashl $r0,$r0,1
+ ashl $r2,$r2,1
+ or $r2,$r2,$r3
+ cmp $r2,$r1
+ jmpc b,1f
+2:
+ sub $r2,$r2,$r1
+ add $r0,$r0,1
+1:
+ add $r28,$r28,1
+ jmpx 31,$r28,1,0b
+ pop $r28
+ # $r0: quotient
+ # $r2: remainder
+ return
+#endif
+#ifdef L_umodsi3
+.global __umodsi3
+__umodsi3:
+ call __udivsi3
+ move $r0,$r2
+ return
+#endif
+#ifdef L_divsi3
+.global __divsi3
+__divsi3:
+ xor $r5,$r0,$r1 # $r5 is sign of result
+ ashr $r2,$r0,31 # $r0 = abs($r0)
+ xor $r0,$r0,$r2
+ sub $r0,$r0,$r2
+ ashr $r2,$r1,31 # $r1 = abs($r1)
+ xor $r1,$r1,$r2
+ sub $r1,$r1,$r2
+ call __udivsi3
+ ashr $r5,$r5,31
+ xor $r0,$r0,$r5
+ sub $r0,$r0,$r5
+ return
+
+#endif
+#ifdef L_modsi3
+.global __modsi3
+__modsi3:
+ move $r5,$r0 # $r5 is sign of result
+ ashr $r2,$r0,31 # $r0 = abs($r0)
+ xor $r0,$r0,$r2
+ sub $r0,$r0,$r2
+ ashr $r2,$r1,31 # $r1 = abs($r1)
+ xor $r1,$r1,$r2
+ sub $r1,$r1,$r2
+ call __umodsi3
+ ashr $r5,$r5,31
+ xor $r0,$r0,$r5
+ sub $r0,$r0,$r5
+ return
+#endif
Index: libgcc/config/ft32/t-ft32
===================================================================
--- libgcc/config/ft32/t-ft32 (revision 234405)
+++ libgcc/config/ft32/t-ft32 (working copy)
@@ -1,3 +1,7 @@
+LIB1ASMSRC = ft32/lib1funcs.S
+LIB1ASMFUNCS = \
+ _udivsi3 _divsi3 _umodsi3 _modsi3
+
LIB2ADD = $(srcdir)/config/ft32/epilog.S $(srcdir)/config/ft32/prolog.S
crti-hw.o: $(srcdir)/config/ft32/crti-hw.S
