From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19746 invoked by alias); 9 Oct 2004 07:05:29 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 19706 invoked from network); 9 Oct 2004 07:05:21 -0000 Received: from unknown (HELO ksg.nudt.edu.cn) (61.187.54.14) by sourceware.org with SMTP; 9 Oct 2004 07:05:21 -0000 Received: from localhost (localhost [127.0.0.1]) by ksg.nudt.edu.cn (CA-JinChen KSG) with SMTP id 1AE3A33DF0 for ; Sat, 9 Oct 2004 15:05:07 +0800 (CST) X-KSG-Checked: Sat Oct 9 15:05:07 2004 Received: from ds20.nudt.edu.cn (unknown [61.187.54.12]) by ksg.nudt.edu.cn (CA-JinChen KSG) with ESMTP id 0C30933DEE for ; Sat, 9 Oct 2004 15:05:07 +0800 (CST) Received: by ds20.nudt.edu.cn (Postfix, from userid 506) id 3B4745AA3E; Sat, 9 Oct 2004 15:18:11 +0800 (HKT) From: Canqun Yang To: Mostafa Hagog Reply-To: Canqun Yang Cc: Ayal Zaks , Richard Henderson , gcc@gcc.gnu.org References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 8bit User-Agent: YH WebMail Program Version 1.5 X-Originating-IP: 220.192.157.16 Subject: =?gb2312?B?UmU6IFNNUyBzY2hlZHVsaW5n?= Message-Id: <20041009071811.3B4745AA3E@ds20.nudt.edu.cn> Date: Sat, 09 Oct 2004 17:55:00 -0000 X-SW-Source: 2004-10/txt/msg00381.txt.bz2 Mostafa Hagog : > > Canqun Yang wrote on 28/09/2004 11:06:29: > > > Hi, all > > > > I tested the Swing Modulo Scheduling of GCC. For > > simple program, the numerical caculation of PI, it > > achieves significant speedup on IA64. But, for little > > bit complex programs, the SMS can hardly work out a > > successful schedule. > > > > The algorithms implemented by Ayal and Mostafa are > > correct. It seems that the SMS itself is wrong. The > > schedule priority order calculated by SMS is much > > different from normal MinDist algorithm. > > SMS prioritizes the nodes using critical patch based > heuristic - the main idea is that instructions that are > on the critical path are less flexible in means of > scheduling. > Why do you think that the priority order should be > according to MinDist algorithm (what is the minimum > distance in this case)? Can you provide an example > that supports this? > > > Besides this, > > SMS is not sensitive to II. Is SMS really wrong? > > The node ordering step in SMS is not sensitive to II > (as mentioned before it is based on critical path > heuristic). However, the scheduling step is sensitive > to II - failing to schedule the nodes of a loop within > II cycles will lead to try scheduling the nodes again > within II + 1 cycles. > > > Mostafa. > An example for SMS. Content 1. Fortran source 'doloop_get_register' was modified to let it return the needed value. 2. vcg file of data dependence graph 3. node order parameters 4. node order calculated by SMS 5. failed schedule The schedule will block on nearly the same insn node while the II is increasing. 6. node order calculated by mindist algorithm mindist is an algorithm for computing the minmum permissible time interval between every pair of operations. It is a time consuming algorithm. Ref. Iterative Modulo Scheduling, B. Ramakrisha Rau, Compiler and Architecture Research, HPL-94-115, 1995. 7. successful schedule 1. Fortran source #define N 32767 double uold[N], vold[N], alpha; void calc3 () { int i; for (i = 0; i < N; i++) { uold[i] += alpha; vold[i] += alpha; } } 2. vcg file of data dependence graph graph: { node: {title: "0_29" info1: "(insn 29 23 30 1 (set (reg:DF 355) (mem/s:DF (reg/f:DI 351 [ ivtmp.19 ]) [3 uold S8 A64])) 25 {*movdf_internal} (nil) (nil)) "} edge: { sourcename: "0_29" targetname: "2_31" label: "0_0"} edge: { sourcename: "0_29" targetname: "1_30" label: "6_0"} node: {title: "1_30" info1: "(insn 30 29 31 1 (set (reg:DF 356) (plus:DF (reg:DF 355) (reg:DF 353 [ alpha.1 ]))) 133 {adddf3} (insn_list:REG_DEP_TRUE 29 (nil)) (expr_list:REG_DEAD (reg:DF 355) (nil))) "} edge: { sourcename: "1_30" targetname: "2_31" label: "7_0"} node: {title: "2_31" info1: "(insn 31 30 35 1 (set (mem/s:DF (post_inc:DI (reg/f:DI 351 [ ivtmp.19 ])) [3 uold S8 A64]) (reg:DF 356)) 25 {*movdf_internal} (insn_list:REG_DEP_TRUE 30 (insn_list:REG_DEP_ANTI 29 (nil))) (expr_list:REG_DEAD (reg:DF 356) (expr_list:REG_INC (reg/f:DI 351 [ ivtmp.19 ]) (nil)))) "} backedge: {color: red sourcename: "2_31" targetname: "2_31" label: "1_1"} backedge: {color: red sourcename: "2_31" targetname: "0_29" label: "1_1"} edge: { sourcename: "2_31" targetname: "6_71" label: "0_0"} backedge: {color: red sourcename: "2_31" targetname: "3_35" label: "1_1"} backedge: {color: red sourcename: "2_31" targetname: "0_29" label: "1_1"} node: {title: "3_35" info1: "(insn 35 31 36 1 (set (reg:DF 357) (mem/s:DF (reg/f:DI 350 [ ivtmp.23 ]) [3 vold S8 A64])) 25 {*movdf_internal} (nil) (nil)) "} edge: { sourcename: "3_35" targetname: "5_37" label: "0_0"} edge: { sourcename: "3_35" targetname: "4_36" label: "6_0"} backedge: {color: red sourcename: "3_35" targetname: "2_31" label: "0_1"} node: {title: "4_36" info1: "(insn 36 35 37 1 (set (reg:DF 358) (plus:DF (reg:DF 353 [ alpha.1 ]) (reg:DF 357))) 133 {adddf3} (insn_list:REG_DEP_TRUE 35 (nil)) (expr_list:REG_DEAD (reg:DF 357) (nil))) "} edge: { sourcename: "4_36" targetname: "5_37" label: "7_0"} node: {title: "5_37" info1: "(insn 37 36 39 1 (set (mem/s:DF (post_inc:DI (reg/f:DI 350 [ ivtmp.23 ])) [3 vold S8 A64]) (reg:DF 358)) 25 {*movdf_internal} (insn_list:REG_DEP_TRUE 36 (insn_list:REG_DEP_ANTI 35 (nil))) (expr_list:REG_DEAD (reg:DF 358) (expr_list:REG_INC (reg/f:DI 350 [ ivtmp.23 ]) (nil)))) "} backedge: {color: red sourcename: "5_37" targetname: "5_37" label: "1_1"} backedge: {color: red sourcename: "5_37" targetname: "3_35" label: "1_1"} edge: { sourcename: "5_37" targetname: "6_71" label: "0_0"} backedge: {color: red sourcename: "5_37" targetname: "3_35" label: "1_1"} backedge: {color: red sourcename: "5_37" targetname: "2_31" label: "0_1"} backedge: {color: red sourcename: "5_37" targetname: "0_29" label: "1_1"} node: {title: "6_71" info1: "(jump_insn 71 40 81 1 (parallel [ (set (pc) (if_then_else (ne (reg:DI 332 ar.lc) (const_int 0 [0x0])) (label_ref 22) (pc))) (set (reg:DI 332 ar.lc) (if_then_else:DI (ne (reg:DI 332 ar.lc) (const_int 0 [0x0])) (plus:DI (reg:DI 332 ar.lc) (const_int -1 [0xffffffffffffffff])) (reg:DI 332 ar.lc))) ]) 223 {doloop_end_internal} (insn_list:REG_DEP_OUTPUT 31 (insn_list:REG_DEP_OUTPUT 37 (nil))) (nil)) "} } 3. node order parameters # ASAP ALAP HEIGHT MOB DEPTH 0 0 0 13 0 0 1 6 6 7 0 6 2 13 13 0 0 13 3 0 0 13 0 0 4 6 6 7 0 6 5 13 13 0 0 13 6 13 13 0 0 13 4. node order calculated by SMS 2, 5, 1, 4, 0, 3, 6 5. failed schedule ;; Function calc3 SMS single-bb-loop SMS doloop SMS built-ddg 7 SMS num-loads 2 SMS num-stores 2 SMS const-doloop 32766 SMS iis 14 14 28 (rec_mii, mii, maxii) Starting with ii=14 Trying to schedule node 2 in (13 .. 27) step 1 Schedule in 13 Trying to schedule node 5 in (27 .. 13) step -1 Schedule in 27 Trying to schedule node 1 in (6 .. -8) step -1 Schedule in 6 Trying to schedule node 4 in (20 .. 6) step -1 Schedule in 20 Trying to schedule node 0 in (14 .. 1) step 1 Starting with ii=15 Trying to schedule node 2 in (13 .. 28) step 1 Schedule in 13 Trying to schedule node 5 in (28 .. 13) step -1 Schedule in 28 Trying to schedule node 1 in (6 .. -9) step -1 Schedule in 6 Trying to schedule node 4 in (21 .. 6) step -1 Schedule in 21 Trying to schedule node 0 in (14 .. 1) step 1 Starting with ii=16 Trying to schedule node 2 in (13 .. 29) step 1 Schedule in 13 Trying to schedule node 5 in (29 .. 13) step -1 Schedule in 29 Trying to schedule node 1 in (6 .. -10) step -1 Schedule in 6 Trying to schedule node 4 in (22 .. 6) step -1 Schedule in 22 Trying to schedule node 0 in (14 .. 1) step 1 Starting with ii=17 Trying to schedule node 2 in (13 .. 30) step 1 Schedule in 13 Trying to schedule node 5 in (30 .. 13) step -1 Schedule in 30 Trying to schedule node 1 in (6 .. -11) step -1 Schedule in 6 Trying to schedule node 4 in (23 .. 6) step -1 Schedule in 23 Trying to schedule node 0 in (14 .. 1) step 1 Starting with ii=18 ...... 6. node order calculated by mindist algorithm 3, 1, 4, 0, 2, 5, 6 7. The successful schedule. ;; Function calc3 SMS single-bb-loop SMS doloop SMS built-ddg 7 SMS num-loads 2 SMS num-stores 2 SMS const-doloop 32766 SMS iis 14 14 28 (rec_mii, mii, maxii) Starting with ii=14 Trying to schedule node 3 in (0 .. 14) step 1 Schedule in 0 Trying to schedule node 1 in (6 .. 20) step 1 Schedule in 6 Trying to schedule node 4 in (6 .. 20) step 1 Schedule in 6 Trying to schedule node 0 in (0 .. -14) step -1 Schedule in 0 Trying to schedule node 2 in (13 .. 13) step 1 Starting with ii=15 Trying to schedule node 3 in (0 .. 15) step 1 Schedule in 0 Trying to schedule node 1 in (6 .. 21) step 1 Schedule in 6 Trying to schedule node 4 in (6 .. 21) step 1 Schedule in 6 Trying to schedule node 0 in (0 .. -15) step -1 Schedule in 0 Trying to schedule node 2 in (13 .. 14) step 1 Schedule in 13 Trying to schedule node 5 in (13 .. 14) step 1 Schedule in 13 SMS succeeded 15 1 (with ii, sc) Canqun Yang Creative Compiler Research Group. National University of Defense Technology, China.