https://github.com/jonathonpenix updated https://github.com/llvm/llvm-project/pull/79372
>From 37cf78919afbfb6eb4e1bc36a3d8fbb678ffd821 Mon Sep 17 00:00:00 2001 From: Jonathon Penix <jpe...@quicinc.com> Date: Tue, 23 Jan 2024 15:10:50 -0800 Subject: [PATCH 1/2] [clang][Driver][RISCV] Honor -m[no-]global-merge for RISC-V The GlobalMerge pass was enabled for RISC-V in [1] and left off by default. My understanding from [2] is that the concern around enabling the pass by default stemmed primarily from GlobalMerge preventing GP relaxation, which negatively impacted a few benchmarks. However, as a) this pass provides code size benefits in some cases and b) this shouldn't be a concern for situations where GP relaxation is disabled anyway, we'd like to be able to manually enable/disable this functionality without having to specify -mllvm flags and in a way that is consistent with other targets (Arm/AArch64). So, leave the pass off by default still, but honor the -m[no]-global-merge flag for RISC-V. [1] https://reviews.llvm.org/D130481 [2] https://reviews.llvm.org/D129178 --- clang/lib/Driver/ToolChains/Clang.cpp | 10 ++++++++++ clang/test/Driver/mglobal-merge.c | 13 +++++++++++++ 2 files changed, 23 insertions(+) diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index bcba7cbbdb58c2..08bbec5881cf7a 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -2129,6 +2129,16 @@ void Clang::AddRISCVTargetArgs(const ArgList &Args, << A->getSpelling() << Val; } } + + // Forward the -mglobal-merge option for explicit control over the pass. + if (Arg *A = Args.getLastArg(options::OPT_mglobal_merge, + options::OPT_mno_global_merge)) { + CmdArgs.push_back("-mllvm"); + if (A->getOption().matches(options::OPT_mno_global_merge)) + CmdArgs.push_back("-riscv-enable-global-merge=false"); + else + CmdArgs.push_back("-riscv-enable-global-merge=true"); + } } void Clang::AddSparcTargetArgs(const ArgList &Args, diff --git a/clang/test/Driver/mglobal-merge.c b/clang/test/Driver/mglobal-merge.c index 4ea7ae03e78f41..d825527536a861 100644 --- a/clang/test/Driver/mglobal-merge.c +++ b/clang/test/Driver/mglobal-merge.c @@ -6,12 +6,17 @@ // RUN: -mno-global-merge // RUN: FileCheck --check-prefix=CHECK-NGM-AARCH64 < %t %s +// RUN: %clang -target riscv32-unknown-unknown -### -fsyntax-only %s 2> %t \ +// RUN: -mno-global-merge +// RUN: FileCheck --check-prefix=CHECK-NGM-RISCV < %t %s + // RUN: %clang -target x86_64-unknown-unknown -### -fsyntax-only %s 2> %t \ // RUN: -mno-global-merge // RUN: FileCheck --check-prefix=CHECK-NONE < %t %s // CHECK-NGM-ARM: "-mllvm" "-arm-global-merge=false" // CHECK-NGM-AARCH64: "-mllvm" "-aarch64-enable-global-merge=false" +// CHECK-NGM-RISCV: "-mllvm" "-riscv-enable-global-merge=false" // RUN: %clang -target armv7-unknown-unknown -### -fsyntax-only %s 2> %t \ // RUN: -mglobal-merge @@ -21,12 +26,17 @@ // RUN: -mglobal-merge // RUN: FileCheck --check-prefix=CHECK-GM-AARCH64 < %t %s +// RUN: %clang -target riscv32-unknown-unknown -### -fsyntax-only %s 2> %t \ +// RUN: -mglobal-merge +// RUN: FileCheck --check-prefix=CHECK-GM-RISCV < %t %s + // RUN: %clang -target x86_64-unknown-unknown -### -fsyntax-only %s 2> %t \ // RUN: -mglobal-merge // RUN: FileCheck --check-prefix=CHECK-NONE < %t %s // CHECK-GM-ARM: "-mllvm" "-arm-global-merge=true" // CHECK-GM-AARCH64: "-mllvm" "-aarch64-enable-global-merge=true" +// CHECK-GM-RISCV: "-mllvm" "-riscv-enable-global-merge=true" // RUN: %clang -target armv7-unknown-unknown -### -fsyntax-only %s 2> %t // RUN: FileCheck --check-prefix=CHECK-NONE < %t %s @@ -34,6 +44,9 @@ // RUN: %clang -target aarch64-unknown-unknown -### -fsyntax-only %s 2> %t // RUN: FileCheck --check-prefix=CHECK-NONE < %t %s +// RUN: %clang -target riscv32-unknown-unknown -### -fsyntax-only %s 2> %t +// RUN: FileCheck --check-prefix=CHECK-NONE < %t %s + // RUN: %clang -target x86_64-unknown-unknown -### -fsyntax-only %s 2> %t // RUN: FileCheck --check-prefix=CHECK-NONE < %t %s >From 3657d76bfbad18bd3a487832284bee2d799f9f99 Mon Sep 17 00:00:00 2001 From: Jonathon Penix <jpe...@quicinc.com> Date: Wed, 24 Jan 2024 15:25:49 -0800 Subject: [PATCH 2/2] Don't explicitly specify =true when passing -riscv-enable-global-merge --- clang/lib/Driver/ToolChains/Clang.cpp | 2 +- clang/test/Driver/mglobal-merge.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index 08bbec5881cf7a..f184575ddc9f39 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -2137,7 +2137,7 @@ void Clang::AddRISCVTargetArgs(const ArgList &Args, if (A->getOption().matches(options::OPT_mno_global_merge)) CmdArgs.push_back("-riscv-enable-global-merge=false"); else - CmdArgs.push_back("-riscv-enable-global-merge=true"); + CmdArgs.push_back("-riscv-enable-global-merge"); } } diff --git a/clang/test/Driver/mglobal-merge.c b/clang/test/Driver/mglobal-merge.c index d825527536a861..544c8496bae9ad 100644 --- a/clang/test/Driver/mglobal-merge.c +++ b/clang/test/Driver/mglobal-merge.c @@ -36,7 +36,7 @@ // CHECK-GM-ARM: "-mllvm" "-arm-global-merge=true" // CHECK-GM-AARCH64: "-mllvm" "-aarch64-enable-global-merge=true" -// CHECK-GM-RISCV: "-mllvm" "-riscv-enable-global-merge=true" +// CHECK-GM-RISCV: "-mllvm" "-riscv-enable-global-merge" // RUN: %clang -target armv7-unknown-unknown -### -fsyntax-only %s 2> %t // RUN: FileCheck --check-prefix=CHECK-NONE < %t %s _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
