[PATCH] D145416: [clang] model 'p' inline asm constraint as reading memory

[Nick Desaulniers via Phabricator via cfe-commits]

nickdesaulniers updated this revision to Diff 502781.
nickdesaulniers added a comment.

- add sema test to validate 'p' inputs as per @efriedma


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D145416/new/

https://reviews.llvm.org/D145416

Files:
  clang/lib/Basic/TargetInfo.cpp
  clang/test/CodeGen/inline-asm-p-constraint.c
  clang/test/Sema/inline-asm-validate.c


Index: clang/test/Sema/inline-asm-validate.c
===================================================================
--- clang/test/Sema/inline-asm-validate.c
+++ clang/test/Sema/inline-asm-validate.c
@@ -2,7 +2,9 @@
 
 unsigned t, r, *p;
 
-int foo (void) {
+void foo (void) {
   __asm__ __volatile__( "stxr   %w[_t], %[_r], [%[_p]]" : [_t] "=&r" (t) : [_p] "p" (p), [_r] "r" (r) : "memory"); // expected-warning{{value size does not match register size specified by the constraint and modifier}} expected-note {{use constraint modifier "w"}}
-  return 1;
+  // Ensure we accept pointer and non-pointer arguments to "p" constrained
+  // inputs.
+  asm (""::"p"(t), "p"(p));
 }
Index: clang/test/CodeGen/inline-asm-p-constraint.c
===================================================================
--- clang/test/CodeGen/inline-asm-p-constraint.c
+++ clang/test/CodeGen/inline-asm-p-constraint.c
@@ -11,5 +11,4 @@
   asm ("":"=r"(x):"p"(&current_task));
 }
 // CHECK: %0 = call i64 asm "", "=r,r"(ptr @current_task) #[[ATTR:[0-9]+]]
-// FIXME: should be memory(read)
-// CHECK: attributes #[[ATTR]] = { nounwind memory(none) }
+// CHECK: attributes #[[ATTR]] = { nounwind memory(read) }
Index: clang/lib/Basic/TargetInfo.cpp
===================================================================
--- clang/lib/Basic/TargetInfo.cpp
+++ clang/lib/Basic/TargetInfo.cpp
@@ -896,14 +896,13 @@
       Info.setAllowsMemory();
       break;
     case 'g': // general register, memory operand or immediate integer.
+    case 'p': // address operand.
     case 'X': // any operand.
       Info.setAllowsRegister();
       Info.setAllowsMemory();
       break;
     case 'E': // immediate floating point.
     case 'F': // immediate floating point.
-    case 'p': // address operand.
-      break;
     case ',': // multiple alternative constraint.  Ignore comma.
       break;
     case '#': // Ignore as constraint.


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