forked from OSchip/llvm-project
397a98d86d
This change adds the new unroll metadata "llvm.loop.unroll.enable" which directs the optimizer to unroll a loop fully if the trip count is known at compile time, and unroll partially if the trip count is not known at compile time. This differs from "llvm.loop.unroll.full" which explicitly does not unroll a loop if the trip count is not known at compile time With this change "#pragma unroll" generates "llvm.loop.unroll.enable" rather than "llvm.loop.unroll.full" metadata. This changes the semantics of "#pragma unroll" slightly to mean "unroll aggressively (fully or partially)" rather than "unroll fully or not at all". The motivating example for this change was some internal code with a loop marked with "#pragma unroll" which only sometimes had a compile-time trip count depending on template magic. When the trip count was a compile-time constant, everything works as expected and the loop is fully unrolled. However, when the trip count was not a compile-time constant the "#pragma unroll" explicitly disabled unrolling of the loop(!). Removing "#pragma unroll" caused the loop to be unrolled partially which was desirable from a performance perspective. llvm-svn: 244467 |
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| .. | ||
| CMakeLists.txt | ||
| Makefile | ||
| ParseAST.cpp | ||
| ParseCXXInlineMethods.cpp | ||
| ParseDecl.cpp | ||
| ParseDeclCXX.cpp | ||
| ParseExpr.cpp | ||
| ParseExprCXX.cpp | ||
| ParseInit.cpp | ||
| ParseObjc.cpp | ||
| ParseOpenMP.cpp | ||
| ParsePragma.cpp | ||
| ParseStmt.cpp | ||
| ParseStmtAsm.cpp | ||
| ParseTemplate.cpp | ||
| ParseTentative.cpp | ||
| Parser.cpp | ||
| RAIIObjectsForParser.h | ||