Hi, On Thu, 30 Aug 2007, Thiemo Seufer wrote:
> > * ppc: adds -fno-section-anchors to OP_CFLAGS, as dyngen isn't prepared > > to deal with the relocs resulting from using section anchors > > Maybe this should be handled more generally then, not ppc specific, like > other "offending" compiler options: check if the compiler knows the > option, if yes, disable the feature. Yeah, like is done for the other additions to OP_CFLAGS, which are guarded by $(call cc-option, ...). > > I solved that by placing one of the T[012] operands into memory > > for HOST_I386, thereby freeing one reg. Here's some justification > > of why that doesn't really cost performance: with three free regs > > GCC is already spilling like mad in the snippets, we just trade one > > of those memory accesses (to stack) with one other mem access to > > the cpu_state structure, which will be in cache. > > Could you back up this assumption with some numbers? :-) I did that downthread. To me the slowdown is not significant enough, although it exists. > > --- qemu-0.9.0.cvs.orig/target-arm/cpu.h 2007-06-24 14:09:48.000000000 > > +0200 > > +++ qemu-0.9.0.cvs/target-arm/cpu.h 2007-08-21 21:38:36.000000000 +0200 > > @@ -52,6 +52,9 @@ typedef uint32_t ARMReadCPFunc(void *opa > > */ > > > > typedef struct CPUARMState { > > +#if defined(HOST_I386) > > + uint32_t t1; > > +#endif > > /* Regs for current mode. */ > > uint32_t regs[16]; > > /* Frequently accessed CPSR bits are stored separately for efficiently. > > diff -urp qemu-0.9.0.cvs.orig/target-arm/exec.h > > qemu-0.9.0.cvs/target-arm/exec.h > > --- qemu-0.9.0.cvs.orig/target-arm/exec.h 2007-06-03 19:44:36.000000000 > > +0200 > > +++ qemu-0.9.0.cvs/target-arm/exec.h 2007-08-21 21:48:48.000000000 > > +0200 > > @@ -23,7 +23,12 @@ > > register struct CPUARMState *env asm(AREG0); > > register uint32_t T0 asm(AREG1); > > register uint32_t T1 asm(AREG2); > > +#ifndef HOST_I386 > > register uint32_t T2 asm(AREG3); > > +#else > > +#define T2 (env->t1) > > +#endif > > T2/t1 mismatch, it seems. Likewise for mips and ppc. Yes, well, I could have named the env member perhaps "temp" :-) I can change it, though. Ciao, Michael.