From 11fd95dc829c969286da2082e4506f10a7363588 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <reid@kleckner.net>
Date: Tue, 30 Jun 2015 16:32:04 +0000
Subject: [PATCH] [clang-cl] Use /arch: to set the base target CPU

The main effect of this change is that /arch:IA32 will use i386 as the
CPU, while clang-cl will continue to default to pentium4 (aka SSE2 plus
the usual other features).

/arch:AVX and /arch:AVX2 will also now enable the other features
available in sandybridge and haswell respectively, which is consistent
with MSDN.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241077 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Driver/Tools.cpp       | 22 ++++++++++++++++++++++
 test/Driver/cl-x86-flags.c | 11 +++++++++--
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index d635d38dd0..bb56c659e8 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1386,6 +1386,28 @@ static const char *getX86TargetCPU(const ArgList &Args,
       return Args.MakeArgString(CPU);
   }
 
+  if (const Arg *A = Args.getLastArg(options::OPT__SLASH_arch)) {
+    // Mapping built by referring to X86TargetInfo::getDefaultFeatures().
+    StringRef Arch = A->getValue();
+    const char *CPU;
+    if (Triple.getArch() == llvm::Triple::x86) {
+      CPU = llvm::StringSwitch<const char *>(Arch)
+                .Case("IA32", "i386")
+                .Case("SSE", "pentium3")
+                .Case("SSE2", "pentium4")
+                .Case("AVX", "sandybridge")
+                .Case("AVX2", "haswell")
+                .Default(nullptr);
+    } else {
+      CPU = llvm::StringSwitch<const char *>(Arch)
+                .Case("AVX", "sandybridge")
+                .Case("AVX2", "haswell")
+                .Default(nullptr);
+    }
+    if (CPU)
+      return CPU;
+  }
+
   // Select the default CPU if none was given (or detection failed).
 
   if (Triple.getArch() != llvm::Triple::x86_64 &&
diff --git a/test/Driver/cl-x86-flags.c b/test/Driver/cl-x86-flags.c
index 5aae4c41d0..d4f7fb5859 100644
--- a/test/Driver/cl-x86-flags.c
+++ b/test/Driver/cl-x86-flags.c
@@ -8,10 +8,10 @@
 // RUN:     --target=i386-pc-win32 -### -- 2>&1 %s | FileCheck -check-prefix=MFLAGS %s
 // MFLAGS-NOT: argument unused during compilation
 
-// -arch:IA32 is no-op.
 // RUN: %clang_cl -m32 -arch:IA32 --target=i386 -### -- 2>&1 %s | FileCheck -check-prefix=IA32 %s
-// IA32-NOT: argument unused during compilation
+// IA32: "-target-cpu" "i386"
 // IA32-NOT: -target-feature
+// IA32-NOT: argument unused during compilation
 
 // RUN: %clang_cl -m32 -arch:ia32 --target=i386 -### -- 2>&1 %s | FileCheck -check-prefix=ia32 %s
 // ia32: argument unused during compilation
@@ -22,6 +22,7 @@
 // IA3264-NOT: -target-feature
 
 // RUN: %clang_cl -m32 -arch:SSE --target=i386 -### -- 2>&1 %s | FileCheck -check-prefix=SSE %s
+// SSE: "-target-cpu" "pentium3"
 // SSE: -target-feature
 // SSE: +sse
 // SSE-NOT: argument unused during compilation
@@ -31,6 +32,7 @@
 // sse-NOT: -target-feature
 
 // RUN: %clang_cl -m32 -arch:SSE2 --target=i386 -### -- 2>&1 %s | FileCheck -check-prefix=SSE2 %s
+// SSE2: "-target-cpu" "pentium4"
 // SSE2: -target-feature
 // SSE2: +sse2
 // SSE2-NOT: argument unused during compilation
@@ -42,12 +44,14 @@
 // RUN: %clang_cl -m64 -arch:SSE --target=x86_64 -### -- 2>&1 %s | FileCheck -check-prefix=SSE64 %s
 // SSE64: argument unused during compilation
 // SSE64-NOT: -target-feature
+// SSE64-NOT: pentium3
 
 // RUN: %clang_cl -m64 -arch:SSE2 --target=x86_64 -### -- 2>&1 %s | FileCheck -check-prefix=SSE264 %s
 // SSE264: argument unused during compilation
 // SSE264-NOT: -target-feature
 
 // RUN: %clang_cl -m32 -arch:AVX --target=i386 -### -- 2>&1 %s | FileCheck -check-prefix=AVX %s
+// AVX: "-target-cpu" "sandybridge"
 // AVX: -target-feature
 // AVX: +avx
 
@@ -56,6 +60,7 @@
 // avx-NOT: -target-feature
 
 // RUN: %clang_cl -m32 -arch:AVX2 --target=i386 -### -- 2>&1 %s | FileCheck -check-prefix=AVX2 %s
+// AVX2: "-target-cpu" "haswell"
 // AVX2: -target-feature
 // AVX2: +avx2
 
@@ -64,6 +69,7 @@
 // avx2-NOT: -target-feature
 
 // RUN: %clang_cl -m64 -arch:AVX --target=x86_64 -### -- 2>&1 %s | FileCheck -check-prefix=AVX64 %s
+// AVX64: "-target-cpu" "sandybridge"
 // AVX64: -target-feature
 // AVX64: +avx
 
@@ -72,6 +78,7 @@
 // avx64-NOT: -target-feature
 
 // RUN: %clang_cl -m64 -arch:AVX2 --target=x86_64 -### -- 2>&1 %s | FileCheck -check-prefix=AVX264 %s
+// AVX264: "-target-cpu" "haswell"
 // AVX264: -target-feature
 // AVX264: +avx2
 
-- 
2.40.0