* SubOne/AddOne functions always return ConstantInt, declare them as such
* Pull code for handling setcc X, cst, where cst is at the end of the range,
or cc is LE or GE up earlier in visitSetCondInst. This reduces #iterations
in some cases.
* Fold: (div X, C1) op C2 -> range check, implementing div.ll:test6 - test9.
llvm-svn: 16588
This takes something like this:
%A = phi int [ 3, %cond_false.0 ], [ 2, %endif.0.i ], [ 2, %endif.1.i ]
%B = div int %tmp.243, 4
and turns it into:
%A = phi int [ 3/4, %cond_false.0 ], [ 2/4, %endif.0.i ], [ 2/4, %endif.1.i ]
which is later simplified (in this case) into %A = 0.
This triggers thousands of times in spec, for example, 269 times in 176.gcc.
This is tested by InstCombine/add.ll:test23 and set.ll:test18.
llvm-svn: 16582
Instcombine (setcc (truncate X), C1).
This occurs THOUSANDS of times in many benchmarks. Particularlly common
seem to be things like (seteq (cast bool X to int), int 0)
This turns it into (seteq bool %X, false), which then becomes (not %X).
llvm-svn: 16567
This is important for several reasons:
1. Benchmarks have lots of code that looks like this (perlbmk in particular):
%tmp.2.i = setne int %tmp.0.i, 128 ; <bool> [#uses=1]
%tmp.6343 = seteq int %tmp.0.i, 1 ; <bool> [#uses=1]
%tmp.63 = and bool %tmp.2.i, %tmp.6343 ; <bool> [#uses=1]
we now fold away the setne, a clear improvement.
2. In the more important cases, such as (X >= 10) & (X < 20), we now produce
smaller code: (X-10) < 10.
3. Perhaps the nicest effect of this patch is that it really helps out the
code generators. In particular, for a 'range test' like the above,
instead of generating this on X86 (the difference on PPC is even more
pronounced):
cmp %EAX, 50
setge %CL
cmp %EAX, 100
setl %AL
and %CL, %AL
cmp %CL, 0
we now generate this:
add %EAX, -50
cmp %EAX, 50
Furthermore, this causes setcc's to be folded into branches more often.
These combinations trigger dozens of times in the spec benchmarks, particularly
in 176.gcc, 186.crafty, 253.perlbmk, 254.gap, & 099.go.
llvm-svn: 16559
Implement (setcc (shl X, C1), C2) folding.
The second one occurs several dozen times in spec. The first was added
just in case. :)
These are tested by shift.ll:test2[12], and div.ll:test5
llvm-svn: 16549
This latent bug was exposed by recent changes, and is tested as:
llvm/test/Regression/Transforms/InstCombine/2004-09-28-BadShiftAndSetCC.llx
llvm-svn: 16546
triggers often, for example:
6x in povray, 1x in gzip, 279x in gcc, 1x in crafty, 8x in eon, 11x in perlbmk,
362x in gap, 4x in vortex, 14 in m88ksim, 211x in 126.gcc, 1x in compress,
11x in ijpeg, and 4x in 147.vortex.
llvm-svn: 16521
Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.
llvm-svn: 16137
assumed that a constant on the RHS of a multiplication was either an
IntConstant or an FPConstant. It checked for an IntConstant and then,
if it did not find one, did a hard cast to an FPConstant. That code
would crash if the RHS were a ConstantExpr that was neither an
IntConstant nor an FPConstant. This version replaces the hard cast
with a dyn_cast. It performs the same way for IntConstants and
FPConstants but does nothing, instead of crashing, for constant
expressions.
The regression test for this change is 2004-07-27-ConstantExprMul.ll.
llvm-svn: 15291
* Test for whether bits are shifted out during the optzn.
If so, the fold is illegal, though it can be handled explicitly for setne/seteq
This fixes the miscompilation of 254.gap last night, which was a latent bug
exposed by other optimizer improvements.
llvm-svn: 15085
actually care about. Someday when the cast instruction is gone, we can do
better here, but this will do for now. This implements
instcombine/cast.ll:test17/18 as well.
llvm-svn: 15018
Chris Lattner