[X86][MS-InlineAsm] Add constraint *m for memory access w/ global var

Constraint `*m` should be used when the address of a variable is passed
as a value. And the constraint is missing for MS inline assembly when sth
is written to the address of the variable.

The missing would cause FE delete the definition of the static varible,
and then result in "undefined reference to xxx" issue.

Reviewed By: xiangzhangllvm

Differential Revision: https://reviews.llvm.org/D113096

Author: KanRobert

clang/test/CodeGen/X86/ms_fmul.c

@@ -18,4 +18,4 @@ void __attribute__ ((naked)) foo(void)
 }}
 
 // CHECK-LABEL: foo
-// CHECK: call void asm sideeffect inteldialect "fmul qword ptr static_const_table[edx + $$240]\0A\09ret"
+// CHECK: call void asm sideeffect inteldialect "fmul qword ptr $0[edx + $$240]\0A\09ret"

clang/test/CodeGen/ms-inline-asm-static-variable.c

@@ -0,0 +1,10 @@
+// REQUIRES: x86-registered-target
+// Check the constraint "*m" of operand arr and the definition of arr is not removed by FE
+// RUN: %clang_cc1 %s -fasm-blocks -triple i386-apple-darwin10 -emit-llvm -o - | FileCheck %s
+
+static int arr[10];
+void t1() {
+  // CHECK: @arr = internal global [10 x i32]
+  // CHECK: call void asm sideeffect inteldialect "mov dword ptr $0[edx * $$4],edx", "=*m,{{.*}}([10 x i32]* @arr)
+  __asm mov  dword ptr arr[edx*4],edx
+}

clang/test/CodeGen/ms-inline-asm-variables.c

@@ -3,19 +3,19 @@
 
 int gVar;
 void t1() {
-  // CHECK: add eax, dword ptr gVar[eax]
+  // CHECK: add eax, dword ptr ${{[0-9]}}[eax]
   __asm add eax, dword ptr gVar[eax]
-  // CHECK: add dword ptr gVar[eax], eax
+  // CHECK: add dword ptr ${{[0-9]}}[eax], eax
   __asm add dword ptr [eax+gVar], eax
-  // CHECK: add ebx, dword ptr gVar[ebx + $$270]
+  // CHECK: add ebx, dword ptr ${{[0-9]}}[ebx + $$270]
   __asm add ebx, dword ptr gVar[271 - 82 + 81 + ebx]
-  // CHECK: add dword ptr gVar[ebx + $$828], ebx
+  // CHECK: add dword ptr ${{[0-9]}}[ebx + $$828], ebx
   __asm add dword ptr [ebx + gVar + 828], ebx
-  // CHECK: add ecx, dword ptr gVar[ecx + ecx * $$4 + $$4590]
+  // CHECK: add ecx, dword ptr ${{[0-9]}}[ecx + ecx * $$4 + $$4590]
   __asm add ecx, dword ptr gVar[4590 + ecx + ecx*4]
-  // CHECK: add dword ptr gVar[ecx + ecx * $$8 + $$73], ecx
+  // CHECK: add dword ptr ${{[0-9]}}[ecx + ecx * $$8 + $$73], ecx
   __asm add dword ptr [gVar + ecx + 45 + 23 - 53 + 60 - 2 + ecx*8], ecx
-  // CHECK: add gVar[ecx + ebx + $$7], eax
+  // CHECK: add ${{[0-9]}}[ecx + ebx + $$7], eax
   __asm add 1 + 1 + 2 + 3[gVar + ecx + ebx], eax
 }
 
@@ -32,4 +32,3 @@ void t2() {
   // CHECK: mov ${{[0-9]}}[ebx + $$47], eax
   __asm mov 5 + 8 + 13 + 21[lVar + ebx], eax
 }
-

llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp

@@ -1758,8 +1758,8 @@ bool X86AsmParser::CreateMemForMSInlineAsm(
   // It is widely common for MS InlineAsm to use a global variable and one/two
   // registers in a mmory expression, and though unaccessible via rip/eip.
   if (IsGlobalLV && (BaseReg || IndexReg)) {
-    Operands.push_back(
-        X86Operand::CreateMem(getPointerWidth(), Disp, Start, End, Size));
+    Operands.push_back(X86Operand::CreateMem(getPointerWidth(), Disp, Start,
+                                             End, Size, Identifier, Decl));
     return false;
   }
   // Otherwise, we set the base register to a non-zero value
@@ -2551,6 +2551,8 @@ bool X86AsmParser::ParseIntelOperand(OperandVector &Operands) {
   StringRef ErrMsg;
   unsigned BaseReg = SM.getBaseReg();
   unsigned IndexReg = SM.getIndexReg();
+  if (IndexReg && BaseReg == X86::RIP)
+    BaseReg = 0;
   unsigned Scale = SM.getScale();
   if (!PtrInOperand)
     Size = SM.getElementSize() << 3;

llvm/test/CodeGen/X86/ms-inline-asm-array.ll

@@ -0,0 +1,22 @@
+; RUN: llc < %s -mcpu=x86-64  | FileCheck %s
+
+@arr = internal global [10 x i32] zeroinitializer, align 16
+
+; CHECK: movl    %edx, arr(,%rdx,4)
+define dso_local i32 @main() #0 {
+entry:
+  call void asm sideeffect inteldialect "mov dword ptr $0[rdx * $$4],edx", "=*m,~{dirflag},~{fpsr},~{flags}"([10 x i32]* @arr) #1, !srcloc !4
+  ret i32 0
+}
+
+attributes #0 = { noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #1 = { nounwind }
+
+!llvm.module.flags = !{!0, !1, !2}
+!llvm.ident = !{!3}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 7, !"uwtable", i32 1}
+!2 = !{i32 7, !"frame-pointer", i32 2}
+!3 = !{!"clang"}
+!4 = !{i64 63}