The (to be) attached code runs about ~15% (4.4 vs 4.2) slower compiled with:
gfortran -O3 -march=native -funroll-loops -ffast-math test.f90
4.4: 5.060s
4.3: 4.376s
4.2: 4.316s
most time would be spent in PD2VAL.
FYI, the cpu is:
cpu family : 15
model : 65
model name : Dual-Core AMD Opteron(tm) Processor 8218
stepping : 2
cpu MHz : 2612.084
cache size : 1024 KB
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt lm 3dnowext
3dnow pni cx16 lahf_lm cmp_legacy svm cr8_legacy
(-march -> -march=k8-sse3 -mcx16 -msahf --param l1-cache-size=64 --param
l1-cache-line-size=64 --param l2-cache-size=1024 -mtune=k8)
on Core2 4.4 is actually faster:
4.4: 4.236s
4.3.0: 4.572s
-march=core2 -mcx16 -msahf --param l1-cache-size=32 --param
l1-cache-line-size=64 -mtune=core2
--
Summary: [4.4 Regression] 15% slowdown of computational kernel
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jv244 at cam dot ac dot uk
GCC host triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38306
