Opened 7 years ago
Last modified 2 years ago
#1611 new enhancement
Restructure checks for inlinable intrinsics
| Reported by: | sjamaan | Owned by: | sjamaan |
|---|---|---|---|
| Priority: | major | Milestone: | 6.0.0 |
| Component: | compiler | Version: | |
| Keywords: | inlining, intrinsics, performance, lfa2, code duplication | Cc: | |
| Estimated difficulty: | medium |
Description (last modified by )
Currently, we have a lot of intrinsics which are inlinable. Sometimes the safe inlineable versions are missing, sometimes the unsafe ones are missing. It also means there is a *lot* of handwritten C code with duplications.
There would be less duplication if the compiler knew that the safe version is actually (roughly) an argument check followed by an unsafe call.
For example:
C_a_i_logis justC_check_realfollowed byC_flonum(a, log(f))C_a_i_flonum_logisC_flonum(a, C_log(C_flonum_magnitude(x)))(it should actually have a_u_in its name)
Same is true for all the arithmetic operators in (chicken flonum). At least for flonums, I think it's quite doable to have just the unsafe version and have some sort of "rewrite" in the compiler which will do the check followed by a call to the unsafe one.
This can be done for a lot of other intrinsics too; think all the char=, char<, char-upcase, etc.
This would give us a lot of faster implementations of safe operations "for free" by rewriting them to the unsafe ones, and if I'm not mistaken, we'd end up with a lot of calls to the "check" procedures, which ties in nicely with lfa2, which means all but the first can be eliminated.
I'm thinking something like this:
(define-intrinsic (chicken.flonum#fp+ x y)
(check-flonum x)
(check-flonum y)
(##core#inline_allocate ("C_a_i_flonum_plus" 4) x y) ;; to be renamed to C_a_u_i_flonum_plus?
)
(define-intrinsic (scheme#integer->char n)
(check-fixnum n 'integer->char)
(##core#inline "C_make_character" (##core#inline "C_unfix" n))
)
This could even replace the definitions in library.scm; then when we are compiling, we could process this code to generate an intrinsics database file, which the compiler can use like types.db. The above define-intrinsic would collapse to a simple define while generating library.so.
When the compiler is compiling with an intrinsics database, it can replace all calls with the inlinable versions.
Perhaps this is simply a more controlled way of doing -emit-inline-file?
This isn't difficult but a lot of work and some care needs to be taken with regards to backwards C API/binary compatibility.
Change History (4)
comment:1 Changed 7 years ago by
| Description: | modified (diff) |
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comment:2 Changed 6 years ago by
| Milestone: | 5.2 → 5.3 |
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comment:3 Changed 5 years ago by
| Milestone: | 5.3 → 5.4 |
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comment:4 Changed 2 years ago by
| Milestone: | 5.4 → 6.0.0 |
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