llvm-svn: 19222

llvm-svn: 19221

  * We can now fold cast instructions into select instructions that
    have at least one constant operand.
  * We now optimize expressions more aggressively based on bits that are
    known to be zero.  These optimizations occur a lot in code that uses
    bitfields even in simple ways.
  * We now turn more cast-cast sequences into AND instructions.  Before we
    would only do this if it if all types were unsigned.  Now only the
    middle type needs to be unsigned (guaranteeing a zero extend).
  * We transform sign extensions into zero extensions in several cases.

This corresponds to these test/Regression/Transforms/InstCombine testcases:
  2004-11-22-Missed-and-fold.ll
  and.ll: test28-29
  cast.ll: test21-24
  and-or-and.ll
  cast-cast-to-and.ll
  zeroext-and-reduce.ll

llvm-svn: 19220

llvm-svn: 19219

llvm-svn: 19218

llvm-svn: 19217

llvm-svn: 19216

llvm-svn: 19215

While we're at it, improve codegen of select instructions.  For this
testcase:

int %test(bool %C, int %A, int %B) {
  %D = select bool %C, int %A, int %B
  ret int %D
}

We used to generate this code:

_test:
        cmpwi cr0, r3, 0
        bne .LBB_test_2 ;
.LBB_test_1:    ;
        b .LBB_test_3   ;
.LBB_test_2:    ;
        or r5, r4, r4
.LBB_test_3:    ;
        or r3, r5, r5
        blr

Now we emit:

_test:
        cmpwi cr0, r3, 0
        bne .LBB_test_2 ;
.LBB_test_1:    ;
        or r4, r5, r5
.LBB_test_2:    ;
        or r3, r4, r4
        blr

-Chris

llvm-svn: 19214

In particular, instead of compiling this:

bool %test(int %A, int %B) {
  %C = setlt int %A, %B
  ret bool %C
}

to this:

test:
        save %sp, -96, %sp
        subcc %i0, %i1, %g0
        bl .LBBtest_1   !
        nop
        ba .LBBtest_2   !
        nop
.LBBtest_1:     !
        or %g0, 1, %i0
        ba .LBBtest_3   !
        nop
.LBBtest_2:     !
        or %g0, 0, %i0
        ba .LBBtest_3   !
        nop
.LBBtest_3:     !
        restore %g0, %g0, %g0
        retl
        nop

We now compile it to this:

test:
        save %sp, -96, %sp
        subcc %i0, %i1, %g0
        or %g0, 1, %i0
        bl .LBBtest_2   !
        nop
.LBBtest_1:     !
        or %g0, %g0, %i0
.LBBtest_2:     !
        restore %g0, %g0, %g0
        retl
        nop

llvm-svn: 19213

SimplifyCFG is one of those passes that we use for final cleanup: it should
not rely on other passes to clean up its garbage.  This fixes the "why are
trivially dead setcc's in the output of gccas" problem.

llvm-svn: 19212

dead instructions.

llvm-svn: 19211

llvm-svn: 19210

llvm-svn: 19209

llvm-svn: 19208

llvm-svn: 19207

correctly omit them for non-Unix operating systems.

llvm-svn: 19206

Make LLVM_ON_UNIX and LLVM_ON_WIN32 available in the makefiles

llvm-svn: 19205

libraries and tools. Thanks to Henrik Bach for this suggestion.

llvm-svn: 19204

llvm-svn: 19203

llvm-svn: 19202

llvm-svn: 19201

* lib/System depends on sbrk(3), make sure we check for it.

llvm-svn: 19200

llvm-svn: 19199

llvm-svn: 19198

* Make library descriptions consistently lower case.

llvm-svn: 19197

* Make subordinate libraries presented with a vertical list instead of all
  listed on a single line.

llvm-svn: 19196

llvm-svn: 19195

library dependencies, for documentation purposes.

llvm-svn: 19194

processed.

llvm-svn: 19193

* Place a try/catch block around the entire tool to Make sure std::string
  exceptions are caught and printed before exiting the tool.
* Make sure we catch unhandled exceptions at the top level so that we don't
  abort with a useless message but indicate than an unhandled exception was
  generated.

llvm-svn: 19192

llvm-svn: 19190

* Add CAN_DLOPEN_SELF so we can determine if dlopen(0) will open the
  program or not.
* Correct a warning messages to be a little more specific on what it checks

llvm-svn: 19184

llvm-svn: 19183

llvm-svn: 19182

llvm-svn: 19181

llvm-svn: 19180

llvm-svn: 19179

llvm-svn: 19178

llvm-svn: 19177