similar to: [LLVMdev] 128-bit PXOR requires SSE2

On Fri, Jan 20, 2012 at 2:47 PM, Nicolas Capens <nicolas.capens at gmail.com> wrote: > Hi all, > > I think I found a bug in LLVM 3.0: When compiling for a target without > SSE2 support, there were some 128-bit PXOR instructions in the generated > code. > > I traced it down to the following definition in X86InstrSSE.td: > >   def FsFLD0SS : I<0xEF, MRMInitReg,

Hi, I noticed a bunch of psuedo instructions used for creation of constants without generating loads. e.g. pxor xmm0, xmm0 Here is an example of what i am referring to snipped from X86InstrSSE.td: def FsFLD0SS : I<0xEF, MRMInitReg, (outs FR32:$dst), (ins), "", [(set FR32:$dst, fp32imm0)]>, Requires<[HasSSE1]>, TB, OpSize; My question is

Hi all, I have a sample test case : $ cat 1.c int foo(int x, int y){ int z = x + y; return z/2; } I tried to get its IR form with clang providing subtarget feature as mmx for target x86_64 $ clang -O3 -mmmx 1.c -S -emit-llvm in the IR generated i can see the subtarget-features as function attribute : "target-features"="+mmx" In the SelectionDAG phase in file

On Aug 11, 2013, at 4:14 AM, "Nuno Lopes" <nunoplopes at sapo.pt> wrote: >> This sounds promising. But we have some requirements that textbook rewriting systems can't handle: >> >> - Expressions are DAGs, not trees. >> - Targets can add custom rewriting rules and override standard rules. >> - Rules will have predicates. Some predicates are static

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

Here's the big RFC. A I've gone through and designed patterns for AVX, I quickly realized that the existing SSE pattern specification, while functional, is less than ideal in terms of maintenance. In particular, a number of nearly-identical patterns are specified all over for nearly-identical instructions. For example: let Constraints = "$src1 = $dst" in { multiclass

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> > >

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

Hi, I'm looking at scalar and packed instructions in X86. The instruction VCOMISS is scalar. May I remove SSEPackedSingle/SSEPackedDouble domain from it? defm VUCOMISS : sse12_ord_cmp<0x2E, FR32, X86cmp, f32, f32mem, loadf32, "ucomiss", SSEPackedSingle>, TB, VEX, VEX_LIG; defm VUCOMISD : sse12_ord_cmp<0x2E, FR64, X86cmp, f64,

On Tuesday 31 March 2009 13:53, Dan Gohman wrote: > > 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

Can someone explain the magic behind the Pat<> construct and tblgen. >From X86InstrSSE.td: def : Pat<(v4f32 (vector_shuffle VR128:$src, (undef), MOVDDUP_shuffle_mask)), (MOVLHPSrr VR128:$src, VR128:$src)>, Requires<[HasSSE1]>; Where's the code in tblgen to emit the matching code for this? I'm trying to extend it so that Pat<> can be used as a

Bill, Sorry if I wasn't clear enough. I wasn't referring to multiclass's that define other classes, but with using patterns inside of a multiclass to reduce redundant code. For example: multiclass IntSubtract<SDNode node> { def _i8 : Pat<(sub GPRI8:$src0, GPRI8:$src1), (ADD_i8 GPRI8:$src0, (NEGATE_i8 GPRI8:$src1))>; def _i32 : Pat<(sub

Is it legal to do something like a !strconcat on a non-string entity? That is, is there some operation that will let me do this (replace SOME_CONCAT with an appropriate operator): (WARNING! Hacked-up tablegen ahead!) multiclass sse_fp_binop_bitwise_rm<bits<8> opc, string OpcodeStr, SDNode OpNode> { // Vector operation emulating scalar (fp)

On Tue, Feb 10, 2009 at 8:27 AM, Villmow, Micah <Micah.Villmow at amd.com> wrote: > Bill, > Sorry if I wasn't clear enough. I wasn't referring to multiclass's that > define other classes, but with using patterns inside of a multiclass to > reduce redundant code. > For example: > multiclass IntSubtract<SDNode node> > { > def _i8 : Pat<(sub

On Mar 23, 2009, at 5:56 PM, David Greene wrote: > Is it legal to do something like a !strconcat on a non-string > entity? That > is, is there some operation that will let me do this (replace > SOME_CONCAT with > an appropriate operator): I don't get it, can you try a simpler example on me? :) -Chris > > > (WARNING! Hacked-up tablegen ahead!) > >

On Tuesday 24 March 2009 10:43, Chris Lattner wrote: > On Mar 23, 2009, at 5:56 PM, David Greene wrote: > > Is it legal to do something like a !strconcat on a non-string > > entity? That > > is, is there some operation that will let me do this (replace > > SOME_CONCAT with > > an appropriate operator): > > I don't get it, can you try a simpler example on

Hello, I have studied register allocation in theoretical aspects and exploring the same in the implementation level. I need a minimal testcase for register spilling to analyze spilling procedure in llvm. I tried with a testcase taking 20 variables but all the 20 variables are getting stored in the stack using %rbp. Maybe my live variable analysis is wrong. Please help me with a minimal testcase

Hello, I need help here. I am able to adjust the vector width through WidestRegister value. When number of iterations=31 and I set vector width=32 it gives <16xi32> and <8xi32> instructions. However if i replicate same behavior with number of iterations=63 and I set vector width=64, no vector instructions are emitted. it should do as previous and gives <32xi32> and

Specifying -no-implicit-float prevents LLVM from using non-GPR registers for purely integer operations. This is useful for operating systems (such as Wind River's VxWorks) that support tasks that do not save all registers on context switch. This presents an interesting problem for variadic functions that may optionally take non-integer arguments (e.g. printf style functions). Should non-GPR

>>> I like the idea of sharing code between IR and MI passes through an >>> abstract interface. I think that later stages in the IR pipeline also >>> need an instruction optimizer instead of a canonicalizer. >>> >>> An alternative approach would be to describe these transformations in a >>> DSL instead of C++. >> >>>