Duncan Sands 3eba667081 Revert commits 96556 and 96640, because commit 96556 breaks the ... dragonegg self-host build. I reverted 96640 in order to revert 96556 (96640 goes on top of 96556), but it also looks like with both of them applied the breakage happens even earlier. The symptom of the 96556 miscompile is the following crash: llvm[3]: Compiling AlphaISelLowering.cpp for Release build cc1plus: /home/duncan/tmp/tmp/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:4982: void llvm::SelectionDAG::ReplaceAllUsesWith(llvm::SDNode*, llvm::SDNode*, llvm::SelectionDAG::DAGUpdateListener*): Assertion `(!From->hasAnyUseOfValue(i) || From->getValueType(i) == To->getValueType(i)) && "Cannot use this version of ReplaceAllUsesWith!"' failed. Stack dump: 0. Running pass 'X86 DAG->DAG Instruction Selection' on function '@_ZN4llvm19AlphaTargetLowering14LowerOperationENS_7SDValueERNS_12SelectionDAGE' g++: Internal error: Aborted (program cc1plus) This occurs when building LLVM using LLVM built by LLVM (via dragonegg). Probably LLVM has miscompiled itself, though it may have miscompiled GCC and/or dragonegg itself: at this point of the self-host build, all of GCC, LLVM and dragonegg were built using LLVM. Unfortunately this kind of thing is extremely hard to debug, and while I did rummage around a bit I didn't find any smoking guns, aka obviously miscompiled code. Found by bisection. r96556 | evancheng | 2010-02-18 03:13:50 +0100 (Thu, 18 Feb 2010) | 5 lines Some dag combiner goodness: Transform br (xor (x, y)) -> br (x != y) Transform br (xor (xor (x,y), 1)) -> br (x == y) Also normalize (and (X, 1) == / != 1 -> (and (X, 1)) != / == 0 to match to "test on x86" and "tst on arm" r96640 | evancheng | 2010-02-19 01:34:39 +0100 (Fri, 19 Feb 2010) | 16 lines Transform (xor (setcc), (setcc)) == / != 1 to (xor (setcc), (setcc)) != / == 1. e.g. On x86_64 %0 = icmp eq i32 %x, 0 %1 = icmp eq i32 %y, 0 %2 = xor i1 %1, %0 br i1 %2, label %bb, label %return => testl %edi, %edi sete %al testl %esi, %esi sete %cl cmpb %al, %cl je LBB1_2 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96672 91177308-0d34-0410-b5e6-96231b3b80d8		2010-02-19 11:30:41 +00:00
..
CallingConvLower.cpp	Change errs() to dbgs().	2010-01-05 01:24:50 +00:00
CMakeLists.txt	Rename SelectionDAGLowering to SelectionDAGBuilder, and rename	2009-11-23 18:04:58 +00:00
DAGCombiner.cpp	Revert commits 96556 and 96640, because commit 96556 breaks the	2010-02-19 11:30:41 +00:00
FastISel.cpp	Fix comments to reflect renaming elsewhere.	2010-02-10 00:11:11 +00:00
FunctionLoweringInfo.cpp	move target-independent opcodes out of TargetInstrInfo	2010-02-09 19:54:29 +00:00
FunctionLoweringInfo.h	Move CopyCatchInfo into FunctionLoweringInfo.cpp too, for consistency.	2009-11-23 18:12:11 +00:00
InstrEmitter.cpp	move target-independent opcodes out of TargetInstrInfo	2010-02-09 19:54:29 +00:00
InstrEmitter.h	Fix a typo in a comment.	2009-11-16 20:35:59 +00:00
LegalizeDAG.cpp	Add non-temporal flags and remove an assumption of default arguments.	2010-02-15 17:00:31 +00:00
LegalizeFloatTypes.cpp	Add non-temporal flags and remove an assumption of default arguments.	2010-02-15 17:00:31 +00:00
LegalizeIntegerTypes.cpp	Add non-temporal flags and remove an assumption of default arguments.	2010-02-15 17:00:31 +00:00
LegalizeTypes.cpp	Add non-temporal flags and remove an assumption of default arguments.	2010-02-15 17:00:31 +00:00
LegalizeTypes.h	It seems better to scalarize vectors of size 1 instead of widening them.	2010-01-24 00:24:43 +00:00
LegalizeTypesGeneric.cpp	Add non-temporal flags and remove an assumption of default arguments.	2010-02-15 17:00:31 +00:00
LegalizeVectorOps.cpp	Revert an earlier change to SIGN_EXTEND_INREG for vectors. The VTSDNode	2010-01-09 02:13:55 +00:00
LegalizeVectorTypes.cpp	Add non-temporal flags and remove an assumption of default arguments.	2010-02-15 17:00:31 +00:00
Makefile	make -fno-rtti the default unless a directory builds with REQUIRES_RTTI.	2010-01-24 20:43:08 +00:00
ScheduleDAGFast.cpp	Trim unneeded includes.	2010-01-21 21:44:43 +00:00
ScheduleDAGList.cpp	Change errs() to dbgs().	2010-01-05 01:24:43 +00:00
ScheduleDAGRRList.cpp	move target-independent opcodes out of TargetInstrInfo	2010-02-09 19:54:29 +00:00
ScheduleDAGSDNodes.cpp	Enable pre-regalloc scheduling load clustering by default.	2010-01-22 23:49:45 +00:00
ScheduleDAGSDNodes.h	Teach pre-regalloc scheduler to schedule loads from nearby addresses. It may improve cache locality. This is controlled by -cluster-loads for now.	2010-01-22 03:36:51 +00:00
SDNodeOrdering.h	Allow 0 as an order number. Don't assign an order to formal arguments.	2009-12-22 21:35:02 +00:00
SelectionDAG.cpp	Make the non-temporal bit "significant" in MemSDNodes so they aren't	2010-02-17 20:21:42 +00:00
SelectionDAGBuilder.cpp	There are two ways of checking for a given type, for example isa<PointerType>(T)	2010-02-16 11:11:14 +00:00
SelectionDAGBuilder.h	Assign the ordering of SDNodes in a much less intrusive fashion. After the	2010-01-28 21:51:40 +00:00
SelectionDAGISel.cpp	sink special case "cannotyetselect" for intrinsics out of the	2010-02-17 06:28:22 +00:00
SelectionDAGPrinter.cpp	Change errs() to dbgs().	2010-01-05 01:24:45 +00:00
TargetLowering.cpp	Revert commits 96556 and 96640, because commit 96556 breaks the	2010-02-19 11:30:41 +00:00