On Wed, Nov 09, 2005 at 07:19:45PM +0100, mathieu lacage wrote: > While the debugging output looks quite correct at -O0, the -O2 output > seems broken: > 00000000 <main>: > 0: 8d 4c 24 04 lea 0x4(%esp),%ecx > 4: 83 e4 f0 and $0xfffffff0,%esp > 7: ff 71 fc pushl 0xfffffffc(%ecx) > a: 55 push %ebp > b: 89 e5 mov %esp,%ebp > d: 53 push %ebx > e: 31 db xor %ebx,%ebx > 10: 51 push %ecx > 11: 83 ec 10 sub $0x10,%esp > 14: 8d b6 00 00 00 00 lea 0x0(%esi),%esi
> With this list of basic block boundaries as reported by the debugging > information: > ad: 0x0 > ad: 0x11 > Clearly, 0x11 is not a bb boundary so we have a bug. Despite the fact No, not clear at all. Every place which could be the target of a jump will be the start of a basic block, but you are not guaranteed that all sequential basic blocks are combined. Probably either Jim's right and it's related to the end of the prologue, or it's a different basic block because of some artifact of inlining. This shouldn't present any problem for a tool using the basic block information. I'm afraid I don't have any useful comments on the patch, but I would like to see GCC generate this information. -- Daniel Jacobowitz CodeSourcery, LLC
