[X86] merge "={eax}" and "~{eax}" into "=&eax" for MSInlineASM

Reviewed By: pengfei

Differential Revision: https://reviews.llvm.org/D94466

diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index a1a72a9..9117500 100644 (file)
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -2483,6 +2483,23 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
       }
     }
 
+    if (isa<MSAsmStmt>(&S)) {
+      if (Clobber == "eax" || Clobber == "edx") {
+        if (Constraints.find("=&A") != std::string::npos)
+          continue;
+        std::string::size_type position1 =
+            Constraints.find("={" + Clobber.str() + "}");
+        if (position1 != std::string::npos) {
+          Constraints.insert(position1 + 1, "&");
+          continue;
+        }
+        std::string::size_type position2 = Constraints.find("=A");
+        if (position2 != std::string::npos) {
+          Constraints.insert(position2 + 1, "&");
+          continue;
+        }
+      }
+    }
     if (!Constraints.empty())
       Constraints += ',';
 

diff --git a/clang/test/CodeGen/ms-inline-asm.c b/clang/test/CodeGen/ms-inline-asm.c
index 1ec5877..d1e3552 100644 (file)
--- a/clang/test/CodeGen/ms-inline-asm.c
+++ b/clang/test/CodeGen/ms-inline-asm.c
@@ -114,7 +114,7 @@ unsigned t10(void) {
 // CHECK: call i32 asm sideeffect inteldialect
 // CHECK-SAME: mov eax, $2
 // CHECK-SAME: mov $0, eax
-// CHECK-SAME: "=*m,={eax},*m,~{eax},~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32* %{{.*}})
+// CHECK-SAME: "=*m,=&{eax},*m,~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32* %{{.*}})
 // CHECK: [[RET:%[a-zA-Z0-9]+]] = load i32, i32* [[J]], align 4
 // CHECK: ret i32 [[RET]]
 }
@@ -140,7 +140,7 @@ unsigned t12(void) {
 // CHECK-SAME: mov $0, eax
 // CHECK-SAME: mov eax, $4
 // CHECK-SAME: mov $1, eax
-// CHECK-SAME: "=*m,=*m,={eax},*m,*m,~{eax},~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32* %{{.*}}, i32* %{{.*}}, i32* %{{.*}})
+// CHECK-SAME: "=*m,=*m,=&{eax},*m,*m,~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32* %{{.*}}, i32* %{{.*}}, i32* %{{.*}})
 }
 
 void t13() {

diff --git a/clang/test/CodeGenCXX/ms-inline-asm-return.cpp b/clang/test/CodeGenCXX/ms-inline-asm-return.cpp
index 4a7165a..c01358c 100644 (file)
--- a/clang/test/CodeGenCXX/ms-inline-asm-return.cpp
+++ b/clang/test/CodeGenCXX/ms-inline-asm-return.cpp
@@ -13,7 +13,17 @@ long long f_i64() {
   }
 }
 // CHECK-LABEL: define dso_local i64 @f_i64()
-// CHECK: %[[r:[^ ]*]] = call i64 asm sideeffect inteldialect "mov eax, $$1\0A\09mov edx, $$1", "=A,~{eax},{{.*}}"
+// CHECK: %[[r:[^ ]*]] = call i64 asm sideeffect inteldialect "mov eax, $$1\0A\09mov edx, $$1", "=&A,{{.*}}"
+// CHECK: ret i64 %[[r]]
+
+long long f_i64_reverse() {
+  __asm {
+    mov edx, 1
+    mov eax, 1
+  }
+}
+// CHECK-LABEL: define dso_local i64 @f_i64_reverse()
+// CHECK: %[[r:[^ ]*]] = call i64 asm sideeffect inteldialect "mov edx, $$1\0A\09mov eax, $$1", "=&A,{{.*}}"
 // CHECK: ret i64 %[[r]]
 
 int f_i32() {
@@ -23,7 +33,26 @@ int f_i32() {
   }
 }
 // CHECK-LABEL: define dso_local i32 @f_i32()
-// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov eax, $$1\0A\09mov edx, $$1", "={eax},~{eax},{{.*}}"
+// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov eax, $$1\0A\09mov edx, $$1", "=&{eax},~{edx},{{.*}}"
+// CHECK: ret i32 %[[r]]
+
+int f_i32_reverse() {
+  __asm {
+    mov edx, 1
+    mov eax, 1
+  }
+}
+// CHECK-LABEL: define dso_local i32 @f_i32_reverse()
+// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov edx, $$1\0A\09mov eax, $$1", "=&{eax},~{edx},{{.*}}"
+// CHECK: ret i32 %[[r]]
+
+int f_i32_edx() {
+  __asm {
+    mov edx, 1
+  }
+}
+// CHECK-LABEL: define dso_local i32 @f_i32_edx()
+// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov edx, $$1", "={eax},~{edx},{{.*}}"
 // CHECK: ret i32 %[[r]]
 
 short f_i16() {
@@ -33,7 +62,7 @@ short f_i16() {
   }
 }
 // CHECK-LABEL: define dso_local signext i16 @f_i16()
-// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov eax, $$1\0A\09mov edx, $$1", "={eax},~{eax},{{.*}}"
+// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov eax, $$1\0A\09mov edx, $$1", "=&{eax},~{edx},{{.*}}"
 // CHECK: %[[r_i16:[^ ]*]] = trunc i32 %[[r]] to i16
 // CHECK: ret i16 %[[r_i16]]
 
@@ -44,7 +73,7 @@ char f_i8() {
   }
 }
 // CHECK-LABEL: define dso_local signext i8 @f_i8()
-// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov eax, $$1\0A\09mov edx, $$1", "={eax},~{eax},{{.*}}"
+// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov eax, $$1\0A\09mov edx, $$1", "=&{eax},~{edx},{{.*}}"
 // CHECK: %[[r_i8:[^ ]*]] = trunc i32 %[[r]] to i8
 // CHECK: ret i8 %[[r_i8]]
 
@@ -55,7 +84,7 @@ bool f_i1() {
   }
 }
 // CHECK-LABEL: define dso_local zeroext i1 @f_i1()
-// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov eax, $$1\0A\09mov edx, $$1", "={eax},~{eax},{{.*}}"
+// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov eax, $$1\0A\09mov edx, $$1", "=&{eax},~{edx},{{.*}}"
 // CHECK: %[[r_i8:[^ ]*]] = trunc i32 %[[r]] to i8
 // CHECK: store i8 %[[r_i8]], i8* %{{.*}}
 // CHECK: %[[r_i1:[^ ]*]] = load i1, i1* %{{.*}}
@@ -70,7 +99,7 @@ FourChars f_s4() {
   }
 }
 // CHECK-LABEL: define dso_local i32 @f_s4()
-// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov eax, $$16843009", "={eax},~{eax},{{.*}}"
+// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "mov eax, $$16843009", "=&{eax},{{.*}}"
 // CHECK: store i32 %[[r]], i32* %{{.*}}
 // CHECK: %[[r_i32:[^ ]*]] = load i32, i32* %{{.*}}
 // CHECK: ret i32 %[[r_i32]]
@@ -85,7 +114,7 @@ EightChars f_s8() {
   }
 }
 // CHECK-LABEL: define dso_local i64 @f_s8()
-// CHECK: %[[r:[^ ]*]] = call i64 asm sideeffect inteldialect "mov eax, $$16843009\0A\09mov edx, $$85", "=A,~{eax},{{.*}}"
+// CHECK: %[[r:[^ ]*]] = call i64 asm sideeffect inteldialect "mov eax, $$16843009\0A\09mov edx, $$85", "=&A,{{.*}}"
 // CHECK: store i64 %[[r]], i64* %{{.*}}
 // CHECK: %[[r_i64:[^ ]*]] = load i64, i64* %{{.*}}
 // CHECK: ret i64 %[[r_i64]]
@@ -96,5 +125,5 @@ int main() {
   __asm xor eax, eax
 }
 // CHECK-LABEL: define dso_local i32 @main()
-// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "xor eax, eax", "={eax},{{.*}}"
+// CHECK: %[[r:[^ ]*]] = call i32 asm sideeffect inteldialect "xor eax, eax", "=&{eax},{{.*}}"
 // CHECK: ret i32 %[[r]]