I'm backing this out for the second time. It was supposed to be fixed by r128164, but the mingw self-host must be defeating the fix.

llvm-svn: 128181

(target-specific branchless method for double-width relational comparisons on x86)

llvm-svn: 128175

Re-apply r127953 with fixes: eliminate empty return block if it has no predecessors; update dominator tree if cfg is modified.

llvm-svn: 127981

to canonicalize IR", it broke a lot of things.

llvm-svn: 127954

to have single return block (at least getting there) for optimizations. This
is general goodness but it would prevent some tailcall optimizations.
One specific case is code like this:
int f1(void);
int f2(void);
int f3(void);
int f4(void);
int f5(void);
int f6(void);
int foo(int x) {
  switch(x) {
  case 1: return f1();
  case 2: return f2();
  case 3: return f3();
  case 4: return f4();
  case 5: return f5();
  case 6: return f6();
  }
}

=>
LBB0_2:                                 ## %sw.bb
  callq   _f1
  popq    %rbp
  ret
LBB0_3:                                 ## %sw.bb1
  callq   _f2
  popq    %rbp
  ret
LBB0_4:                                 ## %sw.bb3
  callq   _f3
  popq    %rbp
  ret

This patch teaches codegenprep to duplicate returns when the return value
is a phi and where the phi operands are produced by tail calls followed by
an unconditional branch:

sw.bb7:                                           ; preds = %entry
  %call8 = tail call i32 @f5() nounwind
  br label %return
sw.bb9:                                           ; preds = %entry
  %call10 = tail call i32 @f6() nounwind
  br label %return
return:
  %retval.0 = phi i32 [ %call10, %sw.bb9 ], [ %call8, %sw.bb7 ], ... [ 0, %entry ]
  ret i32 %retval.0

This allows codegen to generate better code like this:

LBB0_2:                                 ## %sw.bb
        jmp     _f1                     ## TAILCALL
LBB0_3:                                 ## %sw.bb1
        jmp     _f2                     ## TAILCALL
LBB0_4:                                 ## %sw.bb3
        jmp     _f3                     ## TAILCALL

rdar://9147433

llvm-svn: 127953

not have native support for this operation (such as X86).
The legalized code uses two vector INT_TO_FP operations and is faster
than scalarizing.

llvm-svn: 127951

llvm-svn: 127909

comparisons on x86.  Essentially, the way this works is that SUB+SBB sets
the relevant flags the same way a double-width CMP would.

This is a substantial improvement over the generic lowering in LLVM. The output
is also shorter than the gcc-generated output; I haven't done any detailed
benchmarking, though.

llvm-svn: 127852

llvm-svn: 127809

llvm-svn: 127807

rather than an int. Thankfully, this only causes LLVM to miss optimizations, not
generate incorrect code.

This just fixes the zext at the return. We still insert an i32 ZextAssert when
reading a function's arguments, but it is followed by a truncate and another i8
ZextAssert so it is not optimized.

llvm-svn: 127766

corresponding testcases back to the previous versions.

Fixes some performance regressions only seen on 32-bit.

llvm-svn: 127441

llvm-svn: 127382

llvm-svn: 127359

llvm-svn: 127328

Found by inspection.

llvm-svn: 127247

testcases accordingly. Some are currently xfailed and will be filed
as bugs to be fixed or understood.

Performance results:

roughly neutral on SPEC
some micro benchmarks in the llvm suite are up between 100 and 150%, only
a pair of regressions that are due to be investigated

john-the-ripper saw:
10% improvement in traditional DES
8% improvement in BSDI DES
59% improvement in FreeBSD MD5
67% improvement in OpenBSD Blowfish
14% improvement in LM DES

Small compile time impact.

llvm-svn: 127208

llvm-svn: 127175

regs. This is the only change in this checkin that may affects the
default scheduler. With better register tracking and heuristics, it
doesn't make sense to artificially lower the register limit so much.

Added -sched-high-latency-cycles and X86InstrInfo::isHighLatencyDef to
give the scheduler a way to account for div and sqrt on targets that
don't have an itinerary. It is currently defaults to 10 (the actual
number doesn't matter much), but only takes effect on non-default
schedulers: list-hybrid and list-ilp.

Added several heuristics that can be individually disabled for the
non-default sched=list-ilp mode. This helps us determine how much
better we can do on a given benchmark than the default
scheduler. Certain compute intensive loops run much faster in this
mode with the right set of heuristics, and it doesn't seem to have
much negative impact elsewhere. Not all of the heuristics are needed,
but we still need to experiment to decide which should be disabled by
default for sched=list-ilp.

llvm-svn: 127067

      missing patterns for them.

      Add a SIMD test subdirectory to hold tests for SIMD instruction
      selection correctness and quality.
'

llvm-svn: 126845

[AVX] Add decode support for VUNPCKLPS/D instructions, both 128-bit
      and 256-bit forms.  Because the number of elements in a vector
      does not determine the vector type (4 elements could be v4f32 or
      v4f64), pass the full type of the vector to decode routines.

llvm-svn: 126664

llvm-svn: 126518

llvm-svn: 126441

[AVX] General VUNPCKL codegen support.

llvm-svn: 126264

In other words, do not keep track of argument's location.  The debugger (gdb) is not prepared to see line table entries for arguments. For the debugger, "second" line table entry marks beginning of function body.
This requires some coordination with debugger to get this working. 
 - The debugger needs to be aware of prolog_end attribute attached with line table entries.
 - The compiler needs to accurately mark prolog_end in line table entries (at -O0 and at -O1+)

llvm-svn: 126155

since one needs to be a register operand. Just use movss instead of forcing
an operand into a register.

Fixes PR9239

llvm-svn: 126072

llvm-svn: 126018

[AVX] Recorganize X86ShuffleDecode into its own library
(LLVMX86Utils.a) to break cyclic library dependencies between
LLVMX86CodeGen.a and LLVMX86AsmParser.a.  Previously this code was in
a header file and marked static but AVX requires some additional
functionality here that won't be used by all clients.  Since including
unused static functions causes a gcc compiler warning, keeping it as a
header would break builds that use -Werror.  Putting this in its own
library solves both problems at once.

llvm-svn: 125765

other getNode() methods.  Radar 9002173.

llvm-svn: 125665

have their low bits set to zero.  This allows us to optimize
out explicit stack alignment code like in stack-align.ll:test4 when
it is redundant.

Doing this causes the code generator to start turning FI+cst into
FI|cst all over the place, which is general goodness (that is the
canonical form) except that various pieces of the code generator
don't handle OR aggressively.  Fix this by introducing a new
SelectionDAG::isBaseWithConstantOffset predicate, and using it
in places that are looking for ADD(X,CST).  The ARM backend in
particular was missing a lot of addressing mode folding opportunities
around OR.

llvm-svn: 125470

[AVX] Implement 256-bit vector lowering for SCALAR_TO_VECTOR.  This
largely completes support for 128-bit fallback lowering for code that
is not 256-bit ready.

llvm-svn: 125315

[AVX] Implement 256-bit vector lowering for EXTRACT_VECTOR_ELT.

llvm-svn: 125284

[AVX] Implement 256-bit vector lowering for INSERT_VECTOR_ELT.

llvm-svn: 125187

[AVX] Implement BUILD_VECTOR lowering for 256-bit vectors.  For
anything but the simplest of cases, lower a 256-bit BUILD_VECTOR by
splitting it into 128-bit parts and recombining.

llvm-svn: 125105

[AVX] Insert/extract subvector lowering support.  This includes a
couple of utility functions that will be used in other places for more
AVX lowering.

llvm-svn: 125029

Target/X86: Tweak allocating shadow area (aka home) on Win64. It must be enough for caller to allocate one.

llvm-svn: 124949

llvm-svn: 124948

llvm-svn: 124946

[AVX] Revert 124910 until clients are ready.

llvm-svn: 124912

[AVX] Add some utilities to insert and extract 128-bit subvectors.
This allows us to easily support 256-bit operations that don't have
native 256-bit support.  This applies to integer operations, certain
types of shuffles and various othher things.

llvm-svn: 124910