[X86][AsmParser] re-introduce 'offset' operator

Summary:
Amend MS offset operator implementation, to more closely fit with its MS counterpart:

    1. InlineAsm: evaluate non-local source entities to their (address) location
    2. Provide a mean with which one may acquire the address of an assembly label via MS syntax, rather than yielding a memory reference (i.e. "offset asm_label" and "$asm_label" should be synonymous
    3. address PR32530

Based on http://llvm.org/D37461

Fix broken test where the break appears unrelated.

- Set up appropriate memory-input rewrites for variable references.

- Intel-dialect assembly printing now correctly handles addresses by adding "offset".

- Pass offsets as immediate operands (using "r" constraint for offsets of locals).

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D71436

4 files changed, 17 insertions, 6 deletions

diff --git a/clang/test/CodeGen/ms-inline-asm-64.c b/clang/test/CodeGen/ms-inline-asm-64.c
index 5b144eb7bb6..ce46b8821de 100644
--- a/clang/test/CodeGen/ms-inline-asm-64.c
+++ b/clang/test/CodeGen/ms-inline-asm-64.c
@@ -12,10 +12,10 @@ void t1() {
 
 void t2() {
   int var = 10;
-  __asm mov [eax], offset var
+  __asm mov qword ptr [eax], offset var
 // CHECK: t2
 // CHECK: call void asm sideeffect inteldialect
-// CHECK-SAME: mov [eax], $0
+// CHECK-SAME: mov qword ptr [eax], $0
 // CHECK-SAME: "r,~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}})
 }
 
diff --git a/clang/test/CodeGen/ms-inline-asm.c b/clang/test/CodeGen/ms-inline-asm.c
index 0c9b35a6452..17526f52231 100644
--- a/clang/test/CodeGen/ms-inline-asm.c
+++ b/clang/test/CodeGen/ms-inline-asm.c
@@ -190,14 +190,20 @@ void t15() {
 // CHECK: mov eax, $1
   __asm mov eax, offset gvar ; eax = address of gvar
 // CHECK: mov eax, $2
-// CHECK: "*m,r,r,~{eax},~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32* %{{.*}}, i32* @{{.*}})
+  __asm mov eax, offset gvar+1 ; eax = 1 + address of gvar
+// CHECK: mov eax, $3 + $$1
+  __asm mov eax, 1+offset gvar ; eax = 1 + address of gvar
+// CHECK: mov eax, $4 + $$1
+  __asm mov eax, 1+offset gvar+1 ; eax = 2 + address of gvar
+// CHECK: mov eax, $5 + $$2
+// CHECK: "*m,r,i,i,i,i,~{eax},~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}}, i32* %{{.*}}, i32* @{{.*}}, i32* @{{.*}}, i32* @{{.*}}, i32* @{{.*}})
 }
 
 void t16() {
   int var = 10;
-  __asm mov [eax], offset var
+  __asm mov dword ptr [eax], offset var
 // CHECK: t16
-// CHECK: call void asm sideeffect inteldialect "mov [eax], $0", "r,~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}})
+// CHECK: call void asm sideeffect inteldialect "mov dword ptr [eax], $0", "r,~{dirflag},~{fpsr},~{flags}"(i32* %{{.*}})
 }
 
 void t17() {
diff --git a/clang/test/CodeGen/ms-inline-asm.cpp b/clang/test/CodeGen/ms-inline-asm.cpp
index 58796ed6378..463ff0f6e34 100644
--- a/clang/test/CodeGen/ms-inline-asm.cpp
+++ b/clang/test/CodeGen/ms-inline-asm.cpp
@@ -40,7 +40,7 @@ void t2() {
 // CHECK: call void asm sideeffect inteldialect
 // CHECK-SAME: mov eax, $0
 // CHECK-SAME: mov eax, $1
-// CHECK-SAME: "r,r,~{eax},~{dirflag},~{fpsr},~{flags}"(i32** @_ZN3Foo3ptrE, i32** @_ZN3Foo3Bar3ptrE)
+// CHECK-SAME: "i,i,~{eax},~{dirflag},~{fpsr},~{flags}"(i32** @_ZN3Foo3ptrE, i32** @_ZN3Foo3Bar3ptrE)
 }
 
 // CHECK-LABEL: define void @_Z2t3v()
diff --git a/clang/test/Parser/ms-inline-asm.c b/clang/test/Parser/ms-inline-asm.c
index 0170b2b84fa..c6af1ea5126 100644
--- a/clang/test/Parser/ms-inline-asm.c
+++ b/clang/test/Parser/ms-inline-asm.c
@@ -57,6 +57,11 @@ void t13() {
   __asm m{o}v eax, ebx // expected-error {{unknown token in expression}}
 }
 
+void t14() {
+  enum { A = 1, B };
+  __asm mov eax, offset A // expected-error {{offset operator cannot yet handle constants}}
+}
+
 int t_fail() { // expected-note {{to match this}}
   __asm 
   __asm { // expected-error 3 {{expected}} expected-note {{to match this}}