From c2600464c703df5c18fbe057c5ea8a102e0001e4 Mon Sep 17 00:00:00 2001 From: Elliott Hughes Date: Mon, 18 Mar 2024 19:37:13 +0000 Subject: [PATCH] Fully document all the riscv64 flags. In particular, make it clearer when/how we can remove each of them. Change-Id: Ic3156e53ea56479324781fea737390588bc086b5 --- cc/config/riscv64_device.go | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/cc/config/riscv64_device.go b/cc/config/riscv64_device.go index 6a84fee9f..018cd4a39 100644 --- a/cc/config/riscv64_device.go +++ b/cc/config/riscv64_device.go @@ -23,24 +23,36 @@ import ( var ( riscv64Cflags = []string{ - // Help catch common 32/64-bit errors. + // Help catch common 32/64-bit errors. (This is duplicated in all 64-bit + // architectures' cflags.) "-Werror=implicit-function-declaration", + // This is already the driver's Android default, but duplicated here (and + // below) for ease of experimentation with additional extensions. "-march=rv64gcv_zba_zbb_zbs", + // TODO: move to driver (https://github.com/google/android-riscv64/issues/111) "-munaligned-access", - // Until https://gitlab.com/qemu-project/qemu/-/issues/1976 is fixed... + // TODO: remove when qemu V works (https://gitlab.com/qemu-project/qemu/-/issues/1976) + // (Note that we'll probably want to wait for berberis to be good enough + // that most people don't care about qemu's V performance either!) "-mno-implicit-float", - // (https://github.com/google/android-riscv64/issues/124) + // TODO: remove when clang default changed (https://github.com/google/android-riscv64/issues/124) "-mllvm -jump-is-expensive=false", } riscv64ArchVariantCflags = map[string][]string{} riscv64Ldflags = []string{ + // TODO: sysv hashes are the default for other architectures because gnu + // hashes weren't supported until api level 23, but riscv64 didn't exist + // back then, and could move today... + // https://android.googlesource.com/platform/bionic/+/main/android-changes-for-ndk-developers.md#gnu-hashes-availible-in-api-level-23 "-Wl,--hash-style=gnu", + // This is already the driver's Android default, but duplicated here (and + // above) for ease of experimentation with additional extensions. "-march=rv64gcv_zba_zbb_zbs", + // TODO: move to driver (https://github.com/google/android-riscv64/issues/111) "-munaligned-access", - // We should change the default for this in clang, but for now... - // (https://github.com/google/android-riscv64/issues/124) + // TODO: remove when clang default changed (https://github.com/google/android-riscv64/issues/124) "-Wl,-mllvm -Wl,-jump-is-expensive=false", }