aboutsummaryrefslogtreecommitdiff
path: root/test/Transforms/SimplifyCFG
AgeCommit message (Collapse)Author
2011-02-07SimplifyCFG: Track the number of used icmps when turning a icmp chain into a ↵Benjamin Kramer
switch. If we used only one icmp, don't turn it into a switch. Also prevent the switch-to-icmp transform from creating identity adds, noticed by Marius Wachtler. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125056 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-03SimplifyCFG: Also transform switches that represent a range comparison but ↵Benjamin Kramer
are not sorted into sub+icmp. This transforms another 1000 switches in gcc.c. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124826 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02SimplifyCFG: Turn switches into sub+icmp+branch if possible.Benjamin Kramer
This makes the job of the later optzn passes easier, allowing the vast amount of icmp transforms to chew on it. We transform 840 switches in gcc.c, leading to a 16k byte shrink of the resulting binary on i386-linux. The testcase from README.txt now compiles into decl %edi cmpl $3, %edi sbbl %eax, %eax andl $1, %eax ret git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124724 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29Re-apply r124518 with fix. Watch out for invalidated iterator.Evan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124526 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29Revert r124518. It broke Linux self-host.Evan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124522 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29Re-commit r124462 with fixes. Tail recursion elim will now dup ret into ↵Evan Cheng
unconditional predecessor to enable TCE on demand. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124518 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28Revert r124462. There are a few big regressions that I need to fix first.Evan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124478 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28- Stop simplifycfg from duplicating "ret" instructions into unconditionalEvan Cheng
branches. PR8575, rdar://5134905, rdar://8911460. - Allow codegen tail duplication to dup small return blocks after register allocation is done. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124462 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-17SimplifyCFG: Ranges can be larger than 64 bits. Fixes Release-selfhost build.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122054 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-17improve switch formation to handle small range Chris Lattner
comparisons formed by comparisons. For example, this: void foo(unsigned x) { if (x == 0 || x == 1 || x == 3 || x == 4 || x == 6) bar(); } compiles into: _foo: ## @foo ## BB#0: ## %entry cmpl $6, %edi ja LBB0_2 ## BB#1: ## %entry movl %edi, %eax movl $91, %ecx btq %rax, %rcx jb LBB0_3 instead of: _foo: ## @foo ## BB#0: ## %entry cmpl $2, %edi jb LBB0_4 ## BB#1: ## %switch.early.test cmpl $6, %edi ja LBB0_3 ## BB#2: ## %switch.early.test movl %edi, %eax movl $88, %ecx btq %rax, %rcx jb LBB0_4 This catches a bunch of cases in GCC, which look like this: %804 = load i32* @which_alternative, align 4, !tbaa !0 %805 = icmp ult i32 %804, 2 %806 = icmp eq i32 %804, 3 %or.cond121 = or i1 %805, %806 %807 = icmp eq i32 %804, 4 %or.cond124 = or i1 %or.cond121, %807 br i1 %or.cond124, label %.thread, label %808 turning this into a range comparison. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122045 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 - Insert new instructions before DomBlock's terminator,Chris Lattner
which is simpler than finding a place to insert in BB. - Don't perform the 'if condition hoisting' xform on certain i1 PHIs, as it interferes with switch formation. This re-fixes "example 7", without breaking the world hopefully. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121764 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14fix two significant issues with FoldTwoEntryPHINode:Chris Lattner
first, it can kick in on blocks whose conditions have been folded to a constant, even though one of the edges will be trivially folded. second, it doesn't clean up the "if diamond" that it just eliminated away. This is a problem because other simplifycfg xforms kick in depending on the order of block visitation, causing pointless work. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121762 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14fix yet anohter broken lineChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121750 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14reapply my recent change that disables a piece of the switch formationChris Lattner
work, but fixes 400.perlbmk. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121749 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13Fix recent buildbot breakage by pulling SimplifyCFG back to its state as of ↵Owen Anderson
r121694, the most recent state where I'm confident there were no crashes or miscompilations. XFAIL the test added since then for now. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121733 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13temporarily disable part of my previous patch, which causes an iterator ↵Chris Lattner
invalidation issue, causing a crash on some versions of perlbmk. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121728 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13Fix sort predicate. qsort(3)'s predicate semantics differ from std::sort's. ↵Benjamin Kramer
Fixes PR 8780. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121705 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13reinstate my patch: the miscompile was caused by an inverted branch in theChris Lattner
'and' case. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121695 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13Completely disable the optimization I added in r121680 untilChris Lattner
I can track down a miscompile. This should bring the buildbots back to life git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121693 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13Make simplifycfg reprocess newly formed "br (cond1 | cond2)" conditionsChris Lattner
when simplifying, allowing them to be eagerly turned into switches. This is the last step required to get "Example 7" from this blog post: http://blog.regehr.org/archives/320 On X86, we now generate this machine code, which (to my eye) seems better than the ICC generated code: _crud: ## @crud ## BB#0: ## %entry cmpb $33, %dil jb LBB0_4 ## BB#1: ## %switch.early.test addb $-34, %dil cmpb $58, %dil ja LBB0_3 ## BB#2: ## %switch.early.test movzbl %dil, %eax movabsq $288230376537592865, %rcx ## imm = 0x400000017001421 btq %rax, %rcx jb LBB0_4 LBB0_3: ## %lor.rhs xorl %eax, %eax ret LBB0_4: ## %lor.end movl $1, %eax ret git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121690 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13fix a bug in r121680 that upset the various buildbots.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121687 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13make these tests a bit less fragileChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121682 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13enhance the "change or icmp's into switch" xform to handle one value in an Chris Lattner
'or sequence' that it doesn't understand. This allows us to optimize something insane like this: int crud (unsigned char c, unsigned x) { if(((((((((( (int) c <= 32 || (int) c == 46) || (int) c == 44) || (int) c == 58) || (int) c == 59) || (int) c == 60) || (int) c == 62) || (int) c == 34) || (int) c == 92) || (int) c == 39) != 0) foo(); } into: define i32 @crud(i8 zeroext %c, i32 %x) nounwind ssp noredzone { entry: %cmp = icmp ult i8 %c, 33 br i1 %cmp, label %if.then, label %switch.early.test switch.early.test: ; preds = %entry switch i8 %c, label %if.end [ i8 39, label %if.then i8 44, label %if.then i8 58, label %if.then i8 59, label %if.then i8 60, label %if.then i8 62, label %if.then i8 46, label %if.then i8 92, label %if.then i8 34, label %if.then ] by pulling the < comparison out ahead of the newly formed switch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121680 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13merge two testsChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121679 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13Fix my previous patch to handle a degenerate case that the llvm-gccChris Lattner
bootstrap buildbot tripped over. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121674 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13fix a fairly serious oversight with switch formation fromChris Lattner
or'd conditions. Previously we'd compile something like this: int crud (unsigned char c) { return c == 62 || c == 34 || c == 92; } into: switch i8 %c, label %lor.rhs [ i8 62, label %lor.end i8 34, label %lor.end ] lor.rhs: ; preds = %entry %cmp8 = icmp eq i8 %c, 92 br label %lor.end lor.end: ; preds = %entry, %entry, %lor.rhs %0 = phi i1 [ true, %entry ], [ %cmp8, %lor.rhs ], [ true, %entry ] %lor.ext = zext i1 %0 to i32 ret i32 %lor.ext which failed to merge the compare-with-92 into the switch. With this patch we simplify this all the way to: switch i8 %c, label %lor.rhs [ i8 62, label %lor.end i8 34, label %lor.end i8 92, label %lor.end ] lor.rhs: ; preds = %entry br label %lor.end lor.end: ; preds = %entry, %entry, %entry, %lor.rhs %0 = phi i1 [ true, %entry ], [ false, %lor.rhs ], [ true, %entry ], [ true, %entry ] %lor.ext = zext i1 %0 to i32 ret i32 %lor.ext which is much better for codegen's switch lowering stuff. This kicks in 33 times on 176.gcc (for example) cutting 103 instructions off the generated code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121671 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-05Teach SimplifyCFG to turnFrits van Bommel
(indirectbr (select cond, blockaddress(@fn, BlockA), blockaddress(@fn, BlockB))) into (br cond, BlockA, BlockB). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120943 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-11Factor out Instruction::isSafeToSpeculativelyExecute's code forDan Gohman
testing for dereferenceable pointers into a helper function, isDereferenceablePointer. Teach it how to reason about GEPs with simple non-zero indices. Also eliminate ArgumentPromtion's IsAlwaysValidPointer, which didn't check for weak externals or out of range gep indices. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118840 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-24Fix PR8445: a block with no predecessors may be the entry block, in which caseDuncan Sands
it isn't unreachable and should not be zapped. The check for the entry block was missing in one case: a block containing a unwind instruction. While there, do some small cleanups: "M" is not a great name for a Function* (it would be more appropriate for a Module*), change it to "Fn"; use Fn in more places. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117224 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-30Correct bogus module triple specifications.Duncan Sands
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112469 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-16Instead, teach SimplifyCFG to trim non-address-taken blocks fromDan Gohman
indirectbr destination lists. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111122 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-14Teach SimplifyCFG how to simplify indirectbr instructions.Dan Gohman
- Eliminate redundant successors. - Convert an indirectbr with one successor into a direct branch. Also, generalize SimplifyCFG to be able to be run on a function entry block. It knows quite a few simplifications which are applicable to the entry block, and it only needs a few checks to avoid trouble with the entry block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111060 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-13Test case for r105914.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105915 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-08make simplifycfg insert an llvm.trap before the 'unreachable' it introducesChris Lattner
when it detects undefined behavior. llvm.trap generally codegens into some thing really small (e.g. a 2 byte ud2 instruction on x86) and debugging this sort of thing is "nontrivial". For example, we now compile: void foo() { *(int*)0 = 42; } into: _foo: pushl %ebp movl %esp, %ebp ud2 Some may even claim that this is a security hole, though that seems dubious to me. This addresses rdar://7958343 - Optimizing away null dereference potentially allows arbitrary code execution git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103356 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-31testcase for r99914, provided by baldrick!Gabor Greif
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100043 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-02Floating-point add, sub, and mul are now spelled fadd, fsub, and fmul,Dan Gohman
respectively. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97531 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05Teach SimplifyCFG about magic pointer constants.Jakob Stoklund Olesen
Weird code sometimes uses pointer constants other than null. This patch teaches SimplifyCFG to build switch instructions in those cases. Code like this: void f(const char *x) { if (!x) puts("null"); else if ((uintptr_t)x == 1) puts("one"); else if (x == (char*)2 || x == (char*)3) puts("two"); else if ((intptr_t)x == 4) puts("four"); else puts(x); } Now becomes a switch: define void @f(i8* %x) nounwind ssp { entry: %magicptr23 = ptrtoint i8* %x to i64 ; <i64> [#uses=1] switch i64 %magicptr23, label %if.else16 [ i64 0, label %if.then i64 1, label %if.then2 i64 2, label %if.then9 i64 3, label %if.then9 i64 4, label %if.then14 ] Note that LLVM's own DenseMap uses magic pointers. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95439 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05Delete useless trailing semicolons.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92740 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-30fix two bogus tests that the asmparser now rejects.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92303 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-22Implement PR5795 by merging duplicated return blocks. This could go furtherChris Lattner
by merging all returns in a function into a single one, but simplifycfg currently likes to duplicate the return (an unfortunate choice!) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91890 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-22convert to filecheckChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91889 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10Optimize test more.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86714 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10optimize testChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86672 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-31Revert r85667. LoopUnroll currently can't call utility functions whichDan Gohman
auto-update the DominatorTree because it doesn't keep the DominatorTree current while it works. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85670 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-31Merge the enhancements from LoopUnroll's FoldBlockIntoPredecessor intoDan Gohman
MergeBlockIntoPredecessor. This makes SimplifyCFG slightly more aggressive, and makes it unnecessary for LoopUnroll to have its own copy of this code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85667 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-30Add a testcase for the recent duplicate PHI elimination changes.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85636 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-30if basic blocks are destroyed while there are *just* BlockAddress' hanging Chris Lattner
around, then zap them. This is analogous to dangling constantexprs hanging off functions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85627 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-13change simplifycfg to not duplicate 'unwind' instructions. HopefullyChris Lattner
this will increase the likelihood of common code getting sunk towards the unwind. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83996 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-13convert to filecheckChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83995 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-13rename testChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83994 91177308-0d34-0410-b5e6-96231b3b80d8