[CodeGen] Don't evaluate immediate inlineasm arguments using isICE().

Instead, just EvaluateAsInt().

Follow-up to r239549: rsmith points out that isICE() is expensive;
seems like it's not the right concept anyway, as it fails on
`static const' in C, and will actually trigger the assert below on:
    test/Sema/inline-asm-validate-x86.c

llvm-svn: 239651

clang/lib/CodeGen/CGStmt.cpp

@@ -1754,7 +1754,7 @@ llvm::Value* CodeGenFunction::EmitAsmInput(
   // (immediate or symbolic), try to emit it as such.
   if (!Info.allowsRegister() && !Info.allowsMemory()) {
     llvm::APSInt Result;
-    if (InputExpr->isIntegerConstantExpr(Result, getContext()))
+    if (InputExpr->EvaluateAsInt(Result, getContext()))
       return llvm::ConstantInt::get(getLLVMContext(), Result);
     assert(!Info.requiresImmediateConstant() &&
            "Required-immediate inlineasm arg isn't constant?");

clang/test/CodeGen/inline-asm-immediate-ubsan.c

@@ -20,6 +20,11 @@ void test_inlineasm_i() {
 
 // CHECK-LABEL: @test_inlineasm_I
 // CHECK: call void asm sideeffect "int $0", "I{{.*}}"(i32 2)
+// CHECK: call void asm sideeffect "int $0", "I{{.*}}"(i32 3)
 void test_inlineasm_I() {
   __asm__ __volatile__("int %0" :: "I"(1 + 1));
+
+  // Also check a C non-ICE.
+  static const int N = 1;
+  __asm__ __volatile__("int %0" :: "I"(N + 2));
 }