well, you want to unroll whole loop? try to use -funroll-all-loops ~d
On Wednesday 27 August 2003 20:05, Takahashi, Chris wrote: > I've tried that. No change. When using -Os or -O2 (or I think even -O3) > loop unrolling isn't turned on (according to what I've found by looking in > gcc-3.2.3/gcc/toplev.c) > > -Chris Takahashi > > > > -----Original Message----- > From: Dmitry [mailto:di...@mail.ru] > Sent: Wednesday, August 27, 2003 3:13 AM > To: mspgcc-users@lists.sourceforge.net > Subject: Re: [Mspgcc-users] partial loop unrolling. > > > use -fno-unroll-loops > ~d > > On Wednesday 27 August 2003 03:01, Takahashi, Chris wrote: > > The following code creates some interesting asm with the following flags: > > -g -c -Os -fno-force-mem -mmcu=msp430x437 > > > > It looks like it unrolled the loop in 64 byte chunks and is instead > > iterating over that. While this is faster this would hardly ever get run > > so I would rather have it small. > > > > attached are list files with the -fno-force-mem on and off and the C > > file. > > > > If I change the span it iterates over to a nonmultiple of 64 I get the > > expected asm. > > > > My question is what does no-force-mem have to do with this and why isn't > > auto increment addressing being used? In this case it would save quite a > > bit here. > > > > -Chris > > > > --- > > > > #include <msp430x44x.h> > > > > int test() > > { > > unsigned int sum = 0; > > unsigned int *addr; > > > > for (addr = (int *)0x8000; addr != 0x0000; addr++) { > > sum += *addr; > > } > > > > return sum; > > } > > > > ------- > > > > for (addr = (int *)0x8000; addr != 0x0000; addr++) {^M > > 2: 3e 40 00 80 mov #-32768,r14 ;#0x8000 > > sum += *addr;^M > > 6: 2f 5e add @r14, r15 ; > > 8: 1f 5e 02 00 add 2(r14), r15 ; > > c: 1f 5e 04 00 add 4(r14), r15 ; > > 10: 1f 5e 06 00 add 6(r14), r15 ; > > 14: 1f 5e 08 00 add 8(r14), r15 ; > > 18: 1f 5e 0a 00 add 10(r14),r15 ; > > 1c: 1f 5e 0c 00 add 12(r14),r15 ; > > 20: 1f 5e 0e 00 add 14(r14),r15 ; > > 24: 1f 5e 10 00 add 16(r14),r15 ; > > 28: 1f 5e 12 00 add 18(r14),r15 ; > > 2c: 1f 5e 14 00 add 20(r14),r15 ; > > 30: 1f 5e 16 00 add 22(r14),r15 ; > > 34: 1f 5e 18 00 add 24(r14),r15 ; > > 38: 1f 5e 1a 00 add 26(r14),r15 ; > > 3c: 1f 5e 1c 00 add 28(r14),r15 ; > > 40: 1f 5e 1e 00 add 30(r14),r15 ; > > 44: 1f 5e 20 00 add 32(r14),r15 ; > > 48: 1f 5e 22 00 add 34(r14),r15 ; > > 4c: 1f 5e 24 00 add 36(r14),r15 ; > > 50: 1f 5e 26 00 add 38(r14),r15 ; > > 54: 1f 5e 28 00 add 40(r14),r15 ; > > 58: 1f 5e 2a 00 add 42(r14),r15 ; > > 5c: 1f 5e 2c 00 add 44(r14),r15 ; > > 60: 1f 5e 2e 00 add 46(r14),r15 ; > > 64: 1f 5e 30 00 add 48(r14),r15 ; > > 68: 1f 5e 32 00 add 50(r14),r15 ; > > 6c: 1f 5e 34 00 add 52(r14),r15 ; > > 70: 1f 5e 36 00 add 54(r14),r15 ; > > 74: 1f 5e 38 00 add 56(r14),r15 ; > > 78: 1f 5e 3a 00 add 58(r14),r15 ; > > 7c: 1f 5e 3c 00 add 60(r14),r15 ; > > 80: 1f 5e 3e 00 add 62(r14),r15 ; > > 84: 3e 50 40 00 add #64, r14 ;#0x0040 > > 88: be 23 jnz $-130 ;abs 0x6 > > } -- /***************************************************************** ("`-''-/").___..--''"`-._ (\ Dimmy the Wild UA1ACZ `6_ 6 ) `-. ( ).`-.__.`) State Polytechnical Univ. (_Y_.)' ._ ) `._ `. ``-..-' Radio-Physics Departament _..`--'_..-_/ /--'_.' ,' Saint Petersburg, Russia (il),-'' (li),' ((!.-' +7 (812) 5403923, 5585314 *****************************************************************/
