There is some redundancy at the instruction format level in the x86 .td files.
For example, in X86InstrFormats.td:
// SSE1 Instruction Templates:
//
// SSI - SSE1 instructions with XS prefix.
class SSI<bits<8> o, Format F, dag outs, dag ins, string asm,
list<dag>
pattern>
: I<o, F, outs, ins, asm, pattern>, XS, Requires<[HasSSE1]>;
// SSE3 Instruction Templates:
// S3SI - SSE3 instructions with XSrefix.
class S3SI<bits<8> o, Format F, dag outs, dag ins, string asm,
list<dag>
pattern>
: I<o, F, outs, ins, asm, pattern>, XS, Requires<[HasSSE3]>;
The only difference here is the parameter to Requires. There are many more
examples and this gets worse with AVX.
I'd like to propose a refactoring that looks something like this:
// SSE Instruction Templates:
//
// SSI - SSE Instructions with XS prefix
class SSI<bits<8> o, Format F, dag outs, dag ins, string asm,
list<dag>
pattern>
: I<o, F, outs, ins, asm, pattern>, XS;
/./ SSE1 Instruction Templates
//
// S1SI - SSE1 instructions with Xs prefix
class S1SI<bits<8> o, Format F, dag outs, dag ins, string asm,
list<dag>
pattern>
: SSI<o, F, outs, ins, asm, pattern>, Requires<HasSSE1>;
This way we can reuse the SSI class and hide encoding details for many SSE
levels and AVX.
Sound good?
-Dave
On Monday 30 March 2009 16:12, David Greene wrote:> There is some redundancy at the instruction format level in the x86 .td > files. For example, in X86InstrFormats.td: > > // SSE1 Instruction Templates: > // > // SSI - SSE1 instructions with XS prefix. > > class SSI<bits<8> o, Format F, dag outs, dag ins, string asm, list<dag> > pattern> > > : I<o, F, outs, ins, asm, pattern>, XS, Requires<[HasSSE1]>; > > // SSE3 Instruction Templates: > // S3SI - SSE3 instructions with XSrefix. > > class S3SI<bits<8> o, Format F, dag outs, dag ins, string asm, list<dag> > pattern> > > : I<o, F, outs, ins, asm, pattern>, XS, Requires<[HasSSE3]>; > > The only difference here is the parameter to Requires. There are many more > examples and this gets worse with AVX. > > I'd like to propose a refactoring that looks something like this: > > // SSE Instruction Templates: > // > // SSI - SSE Instructions with XS prefix > > class SSI<bits<8> o, Format F, dag outs, dag ins, string asm, list<dag> > pattern> > > : I<o, F, outs, ins, asm, pattern>, XS; > > /./ SSE1 Instruction Templates > // > // S1SI - SSE1 instructions with Xs prefix > > class S1SI<bits<8> o, Format F, dag outs, dag ins, string asm, list<dag> > pattern> > > : SSI<o, F, outs, ins, asm, pattern>, Requires<HasSSE1>;Actually, I meant to keep the existing class names intact to avoid global changes. So what I'm proposing is actually: class SSIb<bits<8> o, Format F, dag outs, dag ins, string asm, list<dag> pattern> : I<o, F, outs, ins, asm, pattern>, XS; class SSI<bits<8> o, Format F, dag outs, dag ins, string asm, list<dag> pattern> : SSIb<o, F, outs, ins, asm, pattern>, Requires<HasSSE1>; -Dave
On Mar 30, 2009, at 2:53 PM, David Greene wrote:> On Monday 30 March 2009 16:12, David Greene wrote: >> There is some redundancy at the instruction format level in the >> x86 .td >> files. For example, in X86InstrFormats.td: >> >> // SSE1 Instruction Templates: >> // >> // SSI - SSE1 instructions with XS prefix. >> >> class SSI<bits<8> o, Format F, dag outs, dag ins, string asm, >> list<dag> >> pattern> >> >> : I<o, F, outs, ins, asm, pattern>, XS, Requires<[HasSSE1]>; >> >> // SSE3 Instruction Templates: >> // S3SI - SSE3 instructions with XSrefix. >> >> class S3SI<bits<8> o, Format F, dag outs, dag ins, string asm, >> list<dag> >> pattern> >> >> : I<o, F, outs, ins, asm, pattern>, XS, Requires<[HasSSE3]>; >> >> The only difference here is the parameter to Requires. There are >> many more >> examples and this gets worse with AVX.[...]> Actually, I meant to keep the existing class names intact to avoid > global > changes. So what I'm proposing is actually: > > class SSIb<bits<8> o, Format F, dag outs, dag ins, string asm, > list<dag> pattern> : I<o, F, outs, ins, asm, pattern>, XS; > > class SSI<bits<8> o, Format F, dag outs, dag ins, string asm, > list<dag> pattern> > : SSIb<o, F, outs, ins, asm, pattern>, Requires<HasSSE1>;Is this just factoring out the ", XS" part? As presented, it looks like this change would introduce more redundancy that it would eliminate. Dan