[Clang] Fix crash for incompatible types in inline assembly

clang/lib/Sema/SemaStmtAsm.cpp

@@ -664,11 +664,16 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
       SmallerValueMentioned |= OutSize < InSize;
     }
 
+    // If the input is an integer register while the output is floating point,
+    // or vice-versa, there is no way they can work together.
+    bool FPTiedToInt = (InputDomain == AD_FP) ^ (OutputDomain == AD_FP);
+
     // If the smaller value wasn't mentioned in the asm string, and if the
     // output was a register, just extend the shorter one to the size of the
     // larger one.
-    if (!SmallerValueMentioned && InputDomain != AD_Other &&
+    if (!SmallerValueMentioned && !FPTiedToInt && InputDomain != AD_Other &&
         OutputConstraintInfos[TiedTo].allowsRegister()) {
+
       // FIXME: GCC supports the OutSize to be 128 at maximum. Currently codegen
       // crash when the size larger than the register size. So we limit it here.
       if (OutTy->isStructureType() &&

clang/test/Sema/asm.c

@@ -365,3 +365,24 @@ void test19(long long x)
   // FIXME: This case should be supported by codegen, but it fails now.
   asm ("" : "=rm" (x): "0" (e)); // expected-error {{unsupported inline asm: input with type 'st_size128' (aka 'struct _st_size128') matching output with type 'long long'}}
 }
+
+typedef int int2 __attribute__((ext_vector_type(2)));
+
+// GH118892
+void test20(char x) {
+  double d;
+  float f;
+
+  asm ("fabs" : "=t" (d): "0" (x)); // expected-error {{unsupported inline asm: input with type 'char' matching output with type 'double'}}
+  asm ("fabs" : "=t" (x): "0" (d)); // expected-error {{unsupported inline asm: input with type 'double' matching output with type 'char'}}
+  asm ("fabs" : "=t" (f): "0" (d)); // no-error
+  asm ("fabs" : "=t" (d): "0" (f)); // no-error
+
+  st_size64 a;
+  asm ("fabs" : "=t" (d): "0" (a)); // expected-error {{unsupported inline asm: input with type 'st_size64' (aka 'struct _st_size64') matching output with type 'double'}}
+  asm ("fabs" : "=t" (a): "0" (d)); // expected-error {{unsupported inline asm: input with type 'double' matching output with type 'st_size64' (aka 'struct _st_size64')}}
+
+  int2 v;
+  asm ("fabs" : "=t" (d): "0" (v)); // expected-error {{unsupported inline asm: input with type 'int2' (vector of 2 'int' values) matching output with type 'double'}}
+  asm ("fabs" : "=t" (v): "0" (d)); // expected-error {{unsupported inline asm: input with type 'double' matching output with type 'int2' (vector of 2 'int' values)}}
+}