Author: Tom Eccles Date: 2026-07-09T10:52:54+01:00 New Revision: 170a479b64ef5837c760b640d04a91ebc950d265
URL: https://github.com/llvm/llvm-project/commit/170a479b64ef5837c760b640d04a91ebc950d265 DIFF: https://github.com/llvm/llvm-project/commit/170a479b64ef5837c760b640d04a91ebc950d265.diff LOG: [flang][Driver] Add option for real sum reassociation (#207377) Compiler driver option for #207371: -freal-sum-reassociation. Disabled by default. Assisted-by: Codex Added: flang/test/Driver/real-sum-reassociation.f90 Modified: clang/include/clang/Options/FlangOptions.td clang/lib/Driver/ToolChains/Flang.cpp flang/include/flang/Frontend/CodeGenOptions.def flang/include/flang/Lower/LoweringOptions.def flang/lib/Frontend/CompilerInvocation.cpp flang/lib/Lower/Bridge.cpp flang/test/Driver/driver-help.f90 flang/test/Lower/split-sum-expression-tree-lowering.f90 Removed: ################################################################################ diff --git a/clang/include/clang/Options/FlangOptions.td b/clang/include/clang/Options/FlangOptions.td index 18242a465341b..bafc063663fe2 100644 --- a/clang/include/clang/Options/FlangOptions.td +++ b/clang/include/clang/Options/FlangOptions.td @@ -310,6 +310,23 @@ def ffast_real_mod : Flag<["-"], "ffast-real-mod">, Group<f_Group>, def fno_fast_real_mod : Flag<["-"], "fno-fast-real-mod">, Group<f_Group>, HelpText<"Disable optimization of MOD for REAL types in presence of -ffast-math">; +defm real_sum_reassociation + : BoolOptionWithoutMarshalling< + "f", "real-sum-reassociation", + PosFlag<SetTrue, [], [], + "Enable Fortran-standard compliant reassociation within " + "individual REAL sum expressions. This may change exact " + "floating-point results">, + NegFlag<SetFalse, [], [], + "Disable reassociation within individual REAL sum " + "expressions">>, + DocBrief<[{ + Enable Fortran-standard compliant reassociation within individual + ``REAL`` sum expressions. This can improve optimization opportunities + and may change exact floating-point results while preserving + standard-conforming Fortran semantics. + }]>; + defm init_global_zero : BoolOptionWithoutMarshalling<"f", "init-global-zero", PosFlag<SetTrue, [], [], "Zero initialize globals without default initialization (default)">, NegFlag<SetFalse, [], [], "Do not zero initialize globals without default initialization">>; diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp index 662c0c8d9bd4a..d9de24fc04f9a 100644 --- a/clang/lib/Driver/ToolChains/Flang.cpp +++ b/clang/lib/Driver/ToolChains/Flang.cpp @@ -240,6 +240,8 @@ void Flang::addCodegenOptions(const ArgList &Args, Args.addOptInFlag(CmdArgs, options::OPT_fexperimental_loop_fusion, options::OPT_fno_experimental_loop_fusion); + Args.addOptInFlag(CmdArgs, options::OPT_freal_sum_reassociation, + options::OPT_fno_real_sum_reassociation); handleInterchangeLoopsArgs(Args, CmdArgs); handleVectorizeLoopsArgs(Args, CmdArgs); diff --git a/flang/include/flang/Frontend/CodeGenOptions.def b/flang/include/flang/Frontend/CodeGenOptions.def index a5907b6edbd97..53ddc20a6e810 100644 --- a/flang/include/flang/Frontend/CodeGenOptions.def +++ b/flang/include/flang/Frontend/CodeGenOptions.def @@ -54,6 +54,7 @@ CODEGENOPT(VectorizeSLP, 1, 0) ///< Enable SLP vectorization. CODEGENOPT(InterchangeLoops, 1, 0) ///< Enable loop interchange. CODEGENOPT(FuseLoops, 1, 0) ///< Enable loop fusion. CODEGENOPT(LoopVersioning, 1, 0) ///< Enable loop versioning. +CODEGENOPT(SplitSumExpressionTree, 1, 0) ///< Split REAL addition expression trees. CODEGENOPT(UnrollLoops, 1, 0) ///< Enable loop unrolling CODEGENOPT(AliasAnalysis, 1, 0) ///< Enable alias analysis pass CODEGENOPT(DwarfVersion, 3, 0) ///< Dwarf version diff --git a/flang/include/flang/Lower/LoweringOptions.def b/flang/include/flang/Lower/LoweringOptions.def index e89ad75704609..0b02ffd5a3b22 100644 --- a/flang/include/flang/Lower/LoweringOptions.def +++ b/flang/include/flang/Lower/LoweringOptions.def @@ -35,6 +35,10 @@ ENUM_LOWERINGOPT(Underscoring, unsigned, 1, 1) /// On by default. ENUM_LOWERINGOPT(ProtectParens, unsigned, 1, 1) +/// If true, split REAL addition expression trees. +/// Off by default. +ENUM_LOWERINGOPT(SplitSumExpressionTree, unsigned, 1, 0) + /// If true, assume the behavior of integer overflow is defined /// (i.e. wraps around as two's complement). Off by default. ENUM_LOWERINGOPT(IntegerWrapAround, unsigned, 1, 0) diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp index cbb094106298f..79ad08353b64c 100644 --- a/flang/lib/Frontend/CompilerInvocation.cpp +++ b/flang/lib/Frontend/CompilerInvocation.cpp @@ -299,6 +299,10 @@ static void parseCodeGenArgs(Fortran::frontend::CodeGenOptions &opts, clang::options::OPT_fno_safe_trampoline, false)) opts.EnableSafeTrampoline = 1; + if (args.hasFlag(clang::options::OPT_freal_sum_reassociation, + clang::options::OPT_fno_real_sum_reassociation, false)) + opts.SplitSumExpressionTree = 1; + if (args.getLastArg(clang::options::OPT_floop_interchange)) opts.InterchangeLoops = 1; @@ -2002,6 +2006,7 @@ void CompilerInvocation::setLoweringOptions() { loweringOpts.setIntegerWrapAround(langOptions.getSignedOverflowBehavior() == Fortran::common::LangOptions::SOB_Defined); loweringOpts.setProtectParens(codegenOpts.ProtectParens); + loweringOpts.setSplitSumExpressionTree(codegenOpts.SplitSumExpressionTree); Fortran::common::MathOptionsBase &mathOpts = loweringOpts.getMathOptions(); // TODO: when LangOptions are finalized, we can represent // the math related options using Fortran::commmon::MathOptionsBase, diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp index 281ad99dc6637..8658a6fb29a44 100644 --- a/flang/lib/Lower/Bridge.cpp +++ b/flang/lib/Lower/Bridge.cpp @@ -91,10 +91,6 @@ static llvm::cl::opt<bool> forceLoopToExecuteOnce( "always-execute-loop-body", llvm::cl::init(false), llvm::cl::desc("force the body of a loop to execute at least once")); -static llvm::cl::opt<bool> enableSplitSumExpressionTreeLowering( - "enable-split-sum-expression-tree-lowering", llvm::cl::Hidden, - llvm::cl::desc("Enable experimental split sum expression tree lowering")); - namespace { /// Information for generating a structured or unstructured increment loop. struct IncrementLoopInfo { @@ -5576,7 +5572,7 @@ class FirConverter : public Fortran::lower::AbstractConverter { auto evaluateRhs = [&](Fortran::lower::StatementContext &stmtCtx) { const Fortran::lower::SomeExpr *rhsExpr = &assign.rhs; std::optional<Fortran::lower::SomeExpr> rewritten; - if (enableSplitSumExpressionTreeLowering && + if (bridge.getLoweringOptions().getSplitSumExpressionTree() && Fortran::evaluate::CanBuildSplitSumExpressionTree(assign.lhs, assign.rhs)) { rewritten = diff --git a/flang/test/Driver/driver-help.f90 b/flang/test/Driver/driver-help.f90 index 4c3609db80b9a..e77fc460850b2 100644 --- a/flang/test/Driver/driver-help.f90 +++ b/flang/test/Driver/driver-help.f90 @@ -7,9 +7,15 @@ ! HELP:USAGE: flang ! HELP-EMPTY: ! HELP-NEXT:OPTIONS: +! HELP: -freal-sum-reassociation +! HELP: Enable Fortran-standard compliant reassociation within individual REAL sum expressions +! HELP: may change exact floating-point results ! HELP-FC1:USAGE: flang ! HELP-FC1-EMPTY: ! HELP-FC1-NEXT:OPTIONS: +! HELP-FC1: -freal-sum-reassociation +! HELP-FC1: Enable Fortran-standard compliant reassociation within individual REAL sum expressions +! HELP-FC1: may change exact floating-point results ! ERROR: error: unknown argument '-helps'; did you mean '-help' diff --git a/flang/test/Driver/real-sum-reassociation.f90 b/flang/test/Driver/real-sum-reassociation.f90 new file mode 100644 index 0000000000000..7d98da0aabb39 --- /dev/null +++ b/flang/test/Driver/real-sum-reassociation.f90 @@ -0,0 +1,27 @@ +! Test driver handling of -freal-sum-reassociation and +! -fno-real-sum-reassociation. + +! RUN: %flang -fsyntax-only -### %s -o %t 2>&1 \ +! RUN: | FileCheck %s --check-prefix=DISABLED + +! RUN: %flang -fsyntax-only -### %s -o %t 2>&1 \ +! RUN: -freal-sum-reassociation \ +! RUN: | FileCheck %s --check-prefix=ENABLED + +! RUN: %flang -fsyntax-only -### %s -o %t 2>&1 \ +! RUN: -fno-real-sum-reassociation \ +! RUN: | FileCheck %s --check-prefix=DISABLED + +! RUN: %flang -fsyntax-only -### %s -o %t 2>&1 \ +! RUN: -fno-real-sum-reassociation -freal-sum-reassociation \ +! RUN: | FileCheck %s --check-prefix=ENABLED + +! RUN: %flang -fsyntax-only -### %s -o %t 2>&1 \ +! RUN: -freal-sum-reassociation -fno-real-sum-reassociation \ +! RUN: | FileCheck %s --check-prefix=DISABLED + +! DISABLED: "-fc1" +! DISABLED-NOT: "-freal-sum-reassociation" + +! ENABLED: "-fc1" +! ENABLED-SAME: "-freal-sum-reassociation" diff --git a/flang/test/Lower/split-sum-expression-tree-lowering.f90 b/flang/test/Lower/split-sum-expression-tree-lowering.f90 index e6287533ed75e..dc89793f7832d 100644 --- a/flang/test/Lower/split-sum-expression-tree-lowering.f90 +++ b/flang/test/Lower/split-sum-expression-tree-lowering.f90 @@ -1,4 +1,5 @@ -! RUN: %flang_fc1 -emit-hlfir -mllvm -enable-split-sum-expression-tree-lowering -o - %s | FileCheck %s --check-prefixes=SPLIT,NO-REWRITE +! RUN: %flang_fc1 -emit-hlfir -freal-sum-reassociation -o - %s | FileCheck %s --check-prefixes=SPLIT,NO-REWRITE +! RUN: %flang_fc1 -emit-hlfir -fno-real-sum-reassociation -o - %s | FileCheck %s --check-prefixes=DEFAULT,NO-REWRITE ! RUN: %flang_fc1 -emit-hlfir -o - %s | FileCheck %s --check-prefixes=DEFAULT,NO-REWRITE ! Default: (((x + a*b) + c*d) + e*f) _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
