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2010-01-121) Use the new SimplifyInstructionsInBlock routine instead of the copyChris Lattner
in JT. 2) When cloning blocks for PHI or xor conditions, use instsimplify to simplify the code as we go. This allows us to squish common cases early in JT which opens up opportunities for subsequent iterations, and allows it to completely simplify the testcase. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93253 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-12Make several tests less fragile.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93230 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-12Teach jump threading to duplicate small blocks when the branchChris Lattner
condition is a xor with a phi node. This eliminates nonsense like this from 176.gcc in several places: LBB166_84: testl %eax, %eax - setne %al - xorb %cl, %al - notb %al - testb $1, %al - je LBB166_85 + je LBB166_69 + jmp LBB166_85 This is rdar://7391699 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93221 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11disable this testcase, PR5997Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93206 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11add one more bitfield optimization, allowing clang to generateChris Lattner
good code on PR4216: _test_bitfield: ## @test_bitfield orl $32962, %edi movl $4294941946, %eax andq %rdi, %rax ret instead of: _test_bitfield: movl $4294941696, %ecx movl %edi, %eax orl $194, %edi orl $32768, %eax andq $250, %rdi andq %rax, %rcx movq %rdi, %rax orq %rcx, %rax ret Evan is looking into the remaining andq+imm -> andl optimization. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93147 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11Extend CanEvaluateZExtd to handle and/or/xor more aggressively in theChris Lattner
BitsToClear case. This allows it to promote expressions which have an and/or/xor after the lshr, promoting cases like test2 (from PR4216) and test3 (random extample extracted from a spec benchmark). clang now compiles the code in PR4216 into: _test_bitfield: ## @test_bitfield movl %edi, %eax orl $194, %eax movl $4294902010, %ecx andq %rax, %rcx orl $32768, %edi andq $39936, %rdi movq %rdi, %rax orq %rcx, %rax ret instead of: _test_bitfield: ## @test_bitfield movl %edi, %eax orl $194, %eax movl $4294902010, %ecx andq %rax, %rcx shrl $8, %edi orl $128, %edi shlq $8, %rdi andq $39936, %rdi movq %rdi, %rax orq %rcx, %rax ret which is still not great, but is progress. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93145 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11Remove the dead TD argument to CanEvaluateZExtd, and add aChris Lattner
new BitsToClear result which allows us to start promoting expressions that end with a lshr-by-constant. This is conservatively correct and better than what we had before (see testcases) but still needs to be extended further. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93144 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10teach sext optimization to handle truncs from types that are notChris Lattner
the dest of the sext. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93128 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10teach zext optimization how to deal with truncs that don't come fromChris Lattner
the zext dest type. This allows us to handle test52/53 in cast.ll, and allows llvm-gcc to generate much better code for PR4216 in -m64 mode: _test_bitfield: ## @test_bitfield orl $32962, %edi movl %edi, %eax andl $-25350, %eax ret This also fixes a bug handling vector extends, ensuring that the mask produced is a vector constant, not an integer constant. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93127 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10now that the cost model has changed, we can always consider Chris Lattner
elimination of a sign extend to be a win, which simplifies the client of CanEvaluateSExtd, and allows us to eliminate more casts (examples taken from real code). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93109 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10change the preferred canonical form for a sign extension to beChris Lattner
lshr+ashr instead of trunc+sext. We want to avoid type conversions whenever possible, it is easier to codegen expressions without truncates and extensions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93107 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10two changes: Chris Lattner
1) don't try to optimize a sext or zext that is only used by a trunc, let the trunc get optimized first. This avoids some pointless effort in some common cases since instcombine scans down a block in the first pass. 2) Change the cost model for zext elimination to consider an 'and' cheaper than a zext. This allows us to do it more aggressively, and for the next patch to simplify the code quite a bit. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93097 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10enhance CanEvaluateZExtd to handle shift left and sext, allowingChris Lattner
more expressions to be promoted and casts eliminated. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93096 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-09Use WriteAsOperand instead of getName() to print loop header names,Dan Gohman
so that unnamed blocks are handled. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93059 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-09only factor from expressions whose uses are empty and whoseChris Lattner
base is the right expression type. This fixes PR5981. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93045 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-08teach instcombine to delete sign extending shift pairs (sra(shl X, C), C) whenChris Lattner
the input is already sign extended. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93019 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-08fix PR5978 by peeling the loop so that we avoid shifting theChris Lattner
result int by 8 for the first byte. While normally harmless, if the result is smaller than a byte, this shift is invalid. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93018 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-07teach ComputeNumSignBits to look through PHI nodes.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92964 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-07filecheckizeChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92963 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-07Enhance instcombine to reason more strongly about promoting computationChris Lattner
that feeds into a zext, similar to the patch I did yesterday for sext. There is a lot of room for extension beyond this patch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92962 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-07fix a globalopt crash on 'bullet' (handling evaluation of a storeChris Lattner
to an element of a vector in a static ctor) which occurs with an unrelated patch I'm testing. Annoyingly, EvaluateStoreInto basically does exactly the same stuff as InsertElement constant folding, but it now handles vectors, and you can't insertelement into a vector. It would be 'really nice' if GEP into a vector were not legal. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92889 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-06Fix a README item: have functionattrs look through selects andDuncan Sands
phi nodes when deciding which pointers point to local memory. I actually checked long ago how useful this is, and it isn't very: it hardly ever fires in the testsuite, but since Chris wants it here it is! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92836 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-06Partially address a README by having functionattrs consider calls toDuncan Sands
memcpy, memset and other intrinsics that only access their arguments to be readnone if the intrinsic's arguments all point to local memory. This improves the testcase in the README to readonly, but it could in theory be made readnone, however this would involve more sophisticated analysis that looks through the memcpy. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92829 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-06Teach instcombine's sext elimination logic to be more aggressive.Chris Lattner
Previously, instcombine would only promote an expression tree to the larger type if doing so eliminated two casts. This is because a need to manually do the sign extend after the promoted expression tree with two shifts. Now, we keep track of whether the result of the computation is going to be properly sign extended already. If so, we can unconditionally promote the expression, which allows us to zap more sext's. This implements rdar://6598839 (aka gcc pr38751) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92815 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05Move this test from test/Transforms/IndVarSimplify toDan Gohman
test/CodeGen/X86, as doesn't use -indvars, and it does use llc -march=x86-64. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92799 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05more rearrangement and cleanup, fix my test failure.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92792 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05remove two trunc xforms that are subsumed by EvaluateInDifferentType.Chris Lattner
The only difference is that EvaluateInDifferentType checks to ensure they are profitable before doing them :) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92788 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05merge some tests.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92786 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05merge cast2 into cast.llChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92784 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05remove useless test.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92782 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05another example.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92781 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05remove a useless negative test, add a rdar # to an xfail that I'm working on.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92777 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05clean up tests.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92776 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05just remove this xform which is subsumed by others.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92775 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05optimize comparisons against cttz/ctlz/ctpop, patch by Alastair Lynn!Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92745 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
2010-01-05optimize cttz and ctlz when we can prove something about the Chris Lattner
leading/trailing bits. Patch by Alastair Lynn! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92706 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05fix an infinite loop in reassociate building emacs.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92679 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05Remove dead debug info intrinsics.Devang Patel
Intrinsic::dbg_stoppoint Intrinsic::dbg_region_start Intrinsic::dbg_region_end Intrinsic::dbg_func_start AutoUpgrade simply ignores these intrinsics now. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92557 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-04Truncate GEP indexes larger than the pointer size down to pointer sizeChris Lattner
when doing this transform if the GEP is not inbounds. No testcase because it is very difficult to trigger this: instcombine already canonicalizes GEP indices to pointer size, so it relies specific permutations of the instcombine worklist. Thanks to Duncan for pointing this possible problem out. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92495 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-04implement an instcombine xform needed by clang's codegenChris Lattner
on the example in PR4216. This doesn't trigger in the testsuite, so I'd really appreciate someone scrutinizing the logic for correctness. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92458 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-03generalize the previous transformation to handle indexing intoChris Lattner
arrays of structs and other arrays, so long as all the subsequent indexes are constants. This triggers frequently for stuff like: @divisions = internal constant [29 x [2 x i32]] [[2 x i32] zeroinitializer, [2 x i32] [i32 0, i32 1], [2 x i32] [i32 0, i32 2], [2 x i32] [i32 0, i32 1], [2 x i32] zeroinitializer, [2 x i32] [i32 0, i32 1], [2 x i32] [i32 0, i32 1], [2 x i32] [i32 0, i32 2], [2 x i32] [i32 0, i32 2], [2 x i32] zeroinitializer, [2 x i32] zeroinitializer, [2 x i32] zeroinitializer, [2 x i32] [i32 0, i32 2], [2 x i32] [i32 0, i32 1], [2 x i32] zeroinitializer, [2 x i32] [i32 1, i32 0], [2 x i32] [i32 1, i32 1], [2 x i32] [i32 1, i32 1], [2 x i32] [i32 1, i32 2], [2 x i32] [i32 1, i32 1], [2 x i32] [i32 1, i32 0], [2 x i32] [i32 1, i32 2], [2 x i32] [i32 1, i32 2], [2 x i32] [i32 1, i32 0], [2 x i32] [i32 1, i32 0], [2 x i32] [i32 1, i32 0], [2 x i32] [i32 1, i32 1], [2 x i32] [i32 1, i32 2], [2 x i32] [i32 1, i32 2]], align 32 ; <[29 x [2 x i32]]*> [#uses=50] %623 = getelementptr inbounds [29 x [2 x i32]]* @divisions, i64 0, i64 %619, i64 0 ; <i32*> [#uses=1] %684 = icmp eq i32 %683, 999 also for the "my_defs" table in 'gs', etc. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92444 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02teach instcombine to optimize idioms like A[i]&42 == 0. ThisChris Lattner
occurs in 403.gcc in mode_mask_array, in safe-ctype.c (which is copied in multiple apps) in _sch_istable, etc. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92427 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02Teach the table lookup optimization to generate range comparesChris Lattner
when a consequtive sequence of elements all satisfies the predicate. Like the double compare case, this generates better code than the magic constant case and generalizes to more than 32/64 element array lookups. Here are some examples where it triggers. From 403.gcc, most accesses to the rtx_class array are handled, e.g.: @rtx_class = constant [153 x i8] c"xxxxxmmmmmmmmxxxxxxxxxxxxmxxxxxxiiixxxxxxxxxxxxxxxxxxxooxooooooxxoooooox3x2c21c2222ccc122222ccccaaaaaa<<<<<<<<<<<<<<<<<<111111111111bbooxxxxxxxxxxcc2211x", align 32 ; <[153 x i8]*> [#uses=547] %142 = icmp eq i8 %141, 105 @rtx_class = constant [153 x i8] c"xxxxxmmmmmmmmxxxxxxxxxxxxmxxxxxxiiixxxxxxxxxxxxxxxxxxxooxooooooxxoooooox3x2c21c2222ccc122222ccccaaaaaa<<<<<<<<<<<<<<<<<<111111111111bbooxxxxxxxxxxcc2211x", align 32 ; <[153 x i8]*> [#uses=543] %165 = icmp eq i8 %164, 60 Also, most of the 59-element arrays (mode_class/rid_to_yy, etc) optimized before are actually range compares. This lets 32-bit machines optimize them. 400.perlbmk has stuff like this: 400.perlbmk: PL_regkind, even for 32-bit: @PL_regkind = constant [62 x i8] c"\00\00\02\02\02\06\06\06\06\09\09\0B\0B\0D\0E\0E\0E\11\12\12\14\14\16\16\18\18\1A\1A\1C\1C\1E\1F !!!$$&'((((,-.///88886789:;8$", align 32 ; <[62 x i8]*> [#uses=4] %811 = icmp ne i8 %810, 33 @PL_utf8skip = constant [256 x i8] c"\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\03\03\03\03\03\03\03\03\03\03\03\03\03\03\03\03\04\04\04\04\04\04\04\04\05\05\05\05\06\06\07\0D", align 32 ; <[256 x i8]*> [#uses=94] %12 = icmp ult i8 %10, 2 etc. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92426 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02Fix logic error in previous commit. The != case needs to become an or, not anNick Lewycky
and. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92419 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02Optimize pointer comparison into the typesafe form, now that the backends willNick Lewycky
handle them efficiently. This is the opposite direction of the transformation we used to have here. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92418 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02Generalize the previous xform to handle cases where exactlyChris Lattner
two elements match or don't match with two comparisons. For example, the testcase compiles into: define i1 @test5(i32 %X) { %1 = icmp eq i32 %X, 2 ; <i1> [#uses=1] %2 = icmp eq i32 %X, 7 ; <i1> [#uses=1] %R = or i1 %1, %2 ; <i1> [#uses=1] ret i1 %R } This generalizes the previous xforms when the array is larger than 64 elements (and this case matches) and generates better code for cases where it overlaps with the magic bitshift case. This generalizes more cases than you might expect. For example, 400.perlbmk has: @PL_utf8skip = constant [256 x i8] c"\01\01\01\... %15 = icmp ult i8 %7, 7 403.gcc has: @rid_to_yy = internal constant [114 x i16] [i16 259, i16 260, ... %18 = icmp eq i16 %16, 295 and xalancbmk has a bunch of examples, such as _ZN11xercesc_2_5L15gCombiningCharsE and _ZN11xercesc_2_5L10gBaseCharsE. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92417 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02enhance the compare/load/index optimization to work on *any* loadChris Lattner
from a global with 32/64 elements or less (depending on whether i64 is native on the target), generating a bitshift idiom to determine the result. For example, on test4 we produce: define i1 @test4(i32 %X) { %1 = lshr i32 933, %X ; <i32> [#uses=1] %2 = and i32 %1, 1 ; <i32> [#uses=1] %R = icmp ne i32 %2, 0 ; <i1> [#uses=1] ret i1 %R } This triggers in a number of interesting cases, for example, here's an fp case: @A.3255 = internal constant [4 x double] [double 4.100000e+00, double -3.900000e+00, double -1.000000e+00, double 1.000000e+00], align 32 ; <[4 x double]*> [#uses=7] ... %7 = fcmp olt double %3, 0.000000e+00 In this case we make the slen2_tab global dead, which is nice: @slen2_tab = internal constant [16 x i32] [i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3, i32 1, i32 2, i32 3, i32 1, i32 2, i32 3, i32 2, i32 3], align 32 ; <[16 x i32]*> [#uses=1] ... %204 = icmp eq i32 %46, 0 Perl has a bunch of these, also on the 'Perl_regkind' array: @Perl_yygindex = internal constant [51 x i16] [i16 0, i16 0, i16 0, i16 0, i16 374, i16 351, i16 0, i16 -12, i16 0, i16 946, i16 413, i16 -83, i16 0, i16 0, i16 0, i16 -311, i16 -13, i16 4007, i16 2893, i16 0, i16 0, i16 0, i16 0, i16 0, i16 372, i16 -8, i16 0, i16 0, i16 246, i16 -131, i16 43, i16 86, i16 208, i16 -45, i16 -169, i16 987, i16 0, i16 0, i16 0, i16 0, i16 308, i16 0, i16 -271, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0], align 32 ; <[51 x i16]*> [#uses=1] ... %1364 = icmp eq i16 %1361, 0 186.crafty really likes this on 64-bit machines, because it triggers on a bunch of globals like this: @white_outpost = internal constant [64 x i8] c"\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\02\02\00\00\00\00\00\04\05\05\04\00\00\00\00\03\06\06\03\00\00\00\00\00\01\01\00\00\00\00\00\00\00\00\00\00\00", align 32 ; <[64 x i8]*> [#uses=2] However the big winner is 403.gcc, which triggers hundreds of times, eliminating all the accesses to the 57-element arrays 'mode_class', mode_unit_size, mode_bitsize, regclass_map, etc. go 64-bit machines :) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92415 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02enhance the previous optimization to work with fcmp in additionChris Lattner
to icmp. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92412 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02Teach instcombine to fold compares of loads from constantChris Lattner
arrays with variable indices into a comparison of the index with a constant. The most common occurrence of this that I see by far is stuff like: if ("foobar"[i] == '\0') ... which we compile into: if (i == 6), saving a load and materialization of the global address. This also exposes loop trip count information to later passes in many cases. This triggers hundreds of times in xalancbmk, which is where I first noticed it, but it also triggers in many other apps. Here are a few interesting ones from various apps: @must_be_connected_without = internal constant [8 x i8*] [i8* getelementptr inbounds ([3 x i8]* @.str64320, i64 0, i64 0), i8* getelementptr inbounds ([3 x i8]* @.str27283, i64 0, i64 0), i8* getelementptr inbounds ([4 x i8]* @.str71327, i64 0, i64 0), i8* getelementptr inbounds ([4 x i8]* @.str72328, i64 0, i64 0), i8* getelementptr inbounds ([3 x i8]* @.str18274, i64 0, i64 0), i8* getelementptr inbounds ([6 x i8]* @.str11267, i64 0, i64 0), i8* getelementptr inbounds ([3 x i8]* @.str32288, i64 0, i64 0), i8* null], align 32 ; <[8 x i8*]*> [#uses=2] %scevgep.i = getelementptr [8 x i8*]* @must_be_connected_without, i64 0, i64 %indvar.i ; <i8**> [#uses=1] %17 = load ... %18 = icmp eq i8* %17, null ; <i1> [#uses=1] -> icmp eq i64 %indvar.i, 7 @yytable1095 = internal constant [84 x i8] c"\12\01(\05\06\07\08\09\0A\0B\0C\0D\0E1\0F\10\11266\1D: \10\11,-,0\03'\10\11B6\04\17&\18\1945\05\06\07\08\09\0A\0B\0C\0D\0E\1E\0F\10\11*\1A\1B\1C$3+>#%;<IJ=ADFEGH9KL\00\00\00C", align 32 ; <[84 x i8]*> [#uses=2] %57 = getelementptr inbounds [84 x i8]* @yytable1095, i64 0, i64 %56 ; <i8*> [#uses=1] %mode.0.in = getelementptr inbounds [9 x i32]* @mb_mode_table, i64 0, i64 %.pn ; <i32*> [#uses=1] load ... %64 = icmp eq i8 %58, 4 ; <i1> [#uses=1] -> icmp eq i64 %.pn, 35 ; <i1> [#uses=0] @gsm_DLB = internal constant [4 x i16] [i16 6554, i16 16384, i16 26214, i16 32767] %scevgep.i = getelementptr [4 x i16]* @gsm_DLB, i64 0, i64 %indvar.i ; <i16*> [#uses=1] %425 = load %scevgep.i %426 = icmp eq i16 %425, -32768 ; <i1> [#uses=0] -> false git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92411 91177308-0d34-0410-b5e6-96231b3b80d8
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