[Bug rtl-optimization/21676] [4.0/4.1/4.2 Regression] Optimizer regression: SciMark sparse matrix benchmark
--- Comment #10 from uros at kss-loka dot si 2006-08-29 06:12 --- (In reply to comment #9) > Fixed on the mainline by: > http://gcc.gnu.org/ml/gcc-patches/2006-08/msg01036.html Not really, the above patch fixed only one of three problems. The other two remains, that is: - ivopts problem (see comment #6) - -march=pentium4 (see comment #8) I'll try to see which option causes problems, described in #8. -- uros at kss-loka dot si changed: What|Removed |Added Summary|[4.0/4.1 Regression]|[4.0/4.1/4.2 Regression] |Optimizer regression: |Optimizer regression: |SciMark sparse matrix |SciMark sparse matrix |benchmark |benchmark http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676
[Bug rtl-optimization/21676] [4.0/4.1/4.2 Regression] Optimizer regression: SciMark sparse matrix benchmark
--- Comment #8 from uros at kss-loka dot si 2006-08-17 07:45 --- Also interesting is, that -march=pentium4 produces following "de-optimized" code, adding a couple more instructions and wasting %eax register: .L8: leal(%ebx,%ebx), %eax movl40(%esp), %edx movl(%edx,%eax,2), %edx movl%edx, (%esp) movl40(%esp), %edx movl4(%edx,%eax,2), %ecx movapd %xmm2, %xmm1 cmpl%ecx, (%esp) jge .L11 movl(%esp), %edx .L12: Some additiona timing can be shown (gcc-4.2 -O2 -fomit-frame-pointer): -march=pentium4: 0m2.756s -march=pentium4 -fno-ivopts: 0m2.500s -march=pentium4 -fno-ivopts -mfpmath=sse: 0m2.461s -msse2 -fno-ivopts -mfmpath=sse: 0m2.311s In the last case, the generated code is equal to gcc-3.2 generated one: .L8: movl36(%esp), %edx movapd %xmm2, %xmm1 movl(%edx,%ebx,4), %eax movl4(%edx,%ebx,4), %ecx cmpl%ecx, %eax jge .L11 movl%eax, %edx .p2align 4,,7 .L12: movl(%edi,%edx,4), %eax movsd (%esi,%eax,8), %xmm0 mulsd (%ebp,%edx,8), %xmm0 addl$1, %edx cmpl%edx, %ecx addsd %xmm0, %xmm1 jg .L12 -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676
[Bug rtl-optimization/21676] [4.0/4.1/4.2 Regression] Optimizer regression: SciMark sparse matrix benchmark
--- Comment #7 from uros at kss-loka dot si 2006-08-17 07:21 --- (In reply to comment #6) > I think that remaining time difference is due to strange loop above innermost: ... due to strange _header_ above innermost loop ... The problem is that we load zero in both arms of "if". This is what I get in .099t.optimized (using gcc-4.2 -O2 -fno-ivopts): :; r.0 = (unsigned int) r; D.1556 = r.0 * 4; rowR = *((int *) D.1556 + row); rowRp1 = *((int *) D.1556 + row + 4B); if (rowR < rowRp1) goto ; else goto ; :; sum = 0.0; goto (); :; i = rowR; sum = 0.0; Assignment to sum should be moved before if... SSE is able to somehow CSE zero load during RTL: .L8: movl 20(%ebp), %edx movapd %xmm2, %xmm1 movl (%edx,%ebx,4), %eax movl 4(%edx,%ebx,4), %ecx cmpl %ecx, %eax jge .L11 movl %eax, %edx .p2align 4,,7 .L12: -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676
[Bug rtl-optimization/21676] [4.0/4.1/4.2 Regression] Optimizer regression: SciMark sparse matrix benchmark
--- Comment #6 from uros at kss-loka dot si 2006-08-16 12:15 --- IMO the problem here is in IVopts. Using gcc-3.x, the innermost loop compiles to: .L15: movl(%edi,%edx,4), %eax fldl(%ebp,%edx,8) addl$1, %edx fmull (%esi,%eax,8) cmpl%ecx, %edx faddp %st, %st(1) jl .L15 and with current SVN gcc-4.2 into: .L12: movl(%ecx), %eax fldl(%ebp,%eax,8) fmull (%edx) faddp %st, %st(1) addl$1, %ebx addl$4, %ecx addl$8, %edx cmpl%esi, %ebx jne .L12 Adding -fno-ivopts, this loop gets compiled into: .L12: movl(%edi,%edx,4), %eax fldl(%esi,%eax,8) fmull (%ebp,%edx,8) faddp %st, %st(1) addl$1, %edx cmpl%edx, %ecx jg .L12 Timings (-O3 -march=pentium4 -fomit-frame-pointer): gcc-3.2: 0m2.301s gcc-4.2: 0m2.713s gcc-4.2 + -fno-ivopts: 0m2.473s with: gcc version 3.2 20020903 (Red Hat Linux 8.0 3.2-7) gcc version 4.2.0 20060816 (experimental) I think that remaining time difference is due to strange loop above innermost: gcc-3.2: fld %st(0) .L16: movl36(%esp), %eax fld %st(0) movl4(%eax,%ebx,4), %ecx movl(%eax,%ebx,4), %edx cmpl%ecx, %edx jge .L23 .L15: movl(%edi,%edx,4), %eax fldl(%ebp,%edx,8) addl$1, %edx fmull (%esi,%eax,8) cmpl%ecx, %edx faddp %st, %st(1) jl .L15 .L23: movl28(%esp), %eax fstpl (%eax,%ebx,8) addl$1, %ebx cmpl24(%esp), %ebx jl .L16 gcc-4.2: .L8: movl36(%esp), %edx movl(%edx,%edi,4), %eax movl4(%edx,%edi,4), %esi fldz cmpl%esi, %eax jge .L11 fstp%st(0) movl40(%esp), %ebx leal(%ebx,%eax,4), %ecx movl32(%esp), %ebx leal(%ebx,%eax,8), %edx fldz xorl%ebx, %ebx subl%eax, %esi .L12: movl(%ecx), %eax fldl(%ebp,%eax,8) fmull (%edx) faddp %st, %st(1) addl$1, %ebx addl$4, %ecx addl$8, %edx cmpl%esi, %ebx jne .L12 .L11: movl28(%esp), %eax fstpl (%eax,%edi,8) addl$1, %edi cmpl24(%esp), %edi jne .L8 and gcc-4.2 -fno-ivopts: .L8: leal(%ebx,%ebx), %eax movl40(%esp), %edx movl(%edx,%eax,2), %edx movl%edx, (%esp) movl40(%esp), %edx movl4(%edx,%eax,2), %ecx fldz cmpl%ecx, (%esp) jge .L11 fstp%st(0) movl(%esp), %edx fldz .L12: movl(%edi,%edx,4), %eax fldl(%esi,%eax,8) fmull (%ebp,%edx,8) faddp %st, %st(1) addl$1, %edx cmpl%edx, %ecx jg .L12 .L11: movl32(%esp), %ecx fstpl (%ecx,%ebx,8) addl$1, %ebx cmpl%ebx, 28(%esp) jg .L8 -- uros at kss-loka dot si changed: What|Removed |Added CC||uros at kss-loka dot si Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Last reconfirmed|-00-00 00:00:00 |2006-08-16 12:15:56 date|| http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676
[Bug rtl-optimization/21676] [4.0/4.1/4.2 Regression] Optimizer regression: SciMark sparse matrix benchmark
--- Comment #5 from pinskia at gcc dot gnu dot org 2006-08-16 06:50 --- Can someone try the mainline again after Paolo B.'s patch? -- pinskia at gcc dot gnu dot org changed: What|Removed |Added Keywords||missed-optimization http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676
[Bug rtl-optimization/21676] [4.0/4.1/4.2 Regression] Optimizer regression: SciMark sparse matrix benchmark
--- Comment #4 from rguenth at gcc dot gnu dot org 2006-07-10 12:45 --- I get on a Pentium 4, -O3 -march=pentium4 -fomit-frame-pointer -o bench Random.i SparseCompRow.i array.i kernel.i main.i 3.4.6: 3.48s 4.0.3: 4.44s 4.1.1: 4.12s 4.2.0: 4.13s -- rguenth at gcc dot gnu dot org changed: What|Removed |Added CC||rguenth at gcc dot gnu dot ||org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676
[Bug rtl-optimization/21676] [4.0/4.1/4.2 Regression] Optimizer regression: SciMark sparse matrix benchmark
--- Comment #3 from gcc at pdoerfler dot com 2006-06-06 11:22 --- I get the following with -O3 -march=pentium4 -fomit-frame-pointer on a pentium4 gentoo machine: gcc-3.4.6 gcc-4.0.2 gcc-4.1.1 2.69s 4.14s 3.26s These are all with gentoo's patches. Also, current mainline is the same as gcc-4.1.1 I can confirm that the difference without -fomit-frame-pointer is much smaller. In fact, 3.4.6 and 4.1.1 are almost the same without it. -- gcc at pdoerfler dot com changed: What|Removed |Added CC||gcc at pdoerfler dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676
[Bug rtl-optimization/21676] [4.0/4.1/4.2 Regression] Optimizer regression: SciMark sparse matrix benchmark
--- Comment #2 from pinskia at gcc dot gnu dot org 2006-06-04 20:06 --- It would be nice if we could get 4.1.x numbers. -- pinskia at gcc dot gnu dot org changed: What|Removed |Added GCC host triplet|i686-pc-linux-gnu | GCC target triplet||i686-pc-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676
[Bug rtl-optimization/21676] [4.0/4.1/4.2 Regression] Optimizer regression: SciMark sparse matrix benchmark
-- jsm28 at gcc dot gnu dot org changed: What|Removed |Added Summary|Optimizer regression: |[4.0/4.1/4.2 Regression] |SciMark sparse matrix |Optimizer regression: |benchmark |SciMark sparse matrix ||benchmark Target Milestone|--- |4.1.2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676
