* config/i386/i386.md (logsf2, logdf2, logxf2, logdf2): New patterns
to implement log, logf and logl built-ins as inline x87 intrinsics.
(UNSPEC_FYL2X): New unspec to represent x87's "fyl2x" instruction.
(*fyl2x_sfxf3, *fyl2x_dfxf3, *fyl2x_xf3, *fyl2x_tfxf3): New insn
patterns for x87's "fyl2x" instruction, used by log?f2 patterns.
* reg-stack.c (subst_stack_regs_pat): Handle UNSPEC_FYL2X like
UNSPEC_FPATAN, i.e. replaces two stack operands with single result.
* gcc.dg/i386-387-1.c: Update to also test log.
* gcc.dg/i386-387-2.c: Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@66709 138bc75d-0d04-0410-961f-82ee72b054a4