Changes in directory llvm/lib/Target:
README.txt updated: 1.43 -> 1.44 --- Log message: For PR950: http://llvm.org/PR950 : Make necessary changes to support DIV -> [SUF]Div. This changes llvm to have three division instructions: signed, unsigned, floating point. The bytecode and assembler are bacwards compatible, however. --- Diffs of the changes: (+13 -0) README.txt | 13 +++++++++++++ 1 files changed, 13 insertions(+) Index: llvm/lib/Target/README.txt diff -u llvm/lib/Target/README.txt:1.43 llvm/lib/Target/README.txt:1.44 --- llvm/lib/Target/README.txt:1.43 Tue Oct 24 11:12:47 2006 +++ llvm/lib/Target/README.txt Thu Oct 26 01:15:43 2006 @@ -319,3 +319,16 @@ } //===---------------------------------------------------------------------===// + +-instcombine should handle this transform: + setcc (sdiv X / C1 ), C2 +when X, C1, and C2 are unsigned. Similarly for udiv and signed operands. + +Currently InstCombine avoids this transform but will do it when the signs of +the operands and the sign of the divide match. See the FIXME in +InstructionCombining.cpp in the visitSetCondInst method after the switch case +for Instruction::UDiv (around line 4447) for more details. + +The SingleSource/Benchmarks/Shootout-C++/hash and hash2 tests have examples of +this construct. +//===---------------------------------------------------------------------===// _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
