Arrange to print constants that match "n" and "i" constraints

in inline asm as signed (what gcc does).  Add partial support
for x86-specific "e" and "Z" constraints, with appropriate
signedness for printing.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64400 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 55 insertions, 3 deletions

diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index fce57f9..909789b 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -2082,8 +2082,11 @@ void TargetLowering::LowerAsmOperandForConstraint(SDValue Op,
     if (C) {   // just C, no GV.
       // Simple constants are not allowed for 's'.
       if (ConstraintLetter != 's') {
-        Ops.push_back(DAG.getTargetConstant(C->getAPIntValue(),
-                                            Op.getValueType()));
+        // gcc prints these as sign extended.  Sign extend value to 64 bits
+        // now; without this it would get ZExt'd later in
+        // ScheduleDAGSDNodes::EmitNode, which is very generic.
+        Ops.push_back(DAG.getTargetConstant(C->getAPIntValue().getSExtValue(),
+                                            MVT::i64));
         return;
       }
     }
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index a3c67e0..46fe216 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -8152,6 +8152,9 @@ X86TargetLowering::getConstraintType(const std::string &Constraint) const {
     case 'y':
     case 'Y':
       return C_RegisterClass;
+    case 'e':
+    case 'Z':
+      return C_Other;
     default:
       break;
     }
@@ -8211,10 +8214,38 @@ void X86TargetLowering::LowerAsmOperandForConstraint(SDValue Op,
       }
     }
     return;
+  case 'e': {
+    // 32-bit signed value
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
+      const ConstantInt *CI = C->getConstantIntValue();
+      if (CI->isValueValidForType(Type::Int32Ty, C->getSExtValue())) {
+        // Widen to 64 bits here to get it sign extended.
+        Result = DAG.getTargetConstant(C->getSExtValue(), MVT::i64);
+        break;
+      }
+    // FIXME gcc accepts some relocatable values here too, but only in certain
+    // memory models; it's complicated.
+    }
+    return;
+  }
+  case 'Z': {
+    // 32-bit unsigned value
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
+      const ConstantInt *CI = C->getConstantIntValue();
+      if (CI->isValueValidForType(Type::Int32Ty, C->getZExtValue())) {
+        Result = DAG.getTargetConstant(C->getZExtValue(), Op.getValueType());
+        break;
+      }
+    }
+    // FIXME gcc accepts some relocatable values here too, but only in certain
+    // memory models; it's complicated.
+    return;
+  }
   case 'i': {
     // Literal immediates are always ok.
     if (ConstantSDNode *CST = dyn_cast<ConstantSDNode>(Op)) {
-      Result = DAG.getTargetConstant(CST->getZExtValue(), Op.getValueType());
+      // Widen to 64 bits here to get it sign extended.
+      Result = DAG.getTargetConstant(CST->getSExtValue(), MVT::i64);
       break;
     }
 
diff --git a/test/CodeGen/X86/2009-02-12-InlineAsm-nieZ-constraints.ll b/test/CodeGen/X86/2009-02-12-InlineAsm-nieZ-constraints.ll
new file mode 100644
index 0000000..ddd15f7
--- /dev/null
+++ b/test/CodeGen/X86/2009-02-12-InlineAsm-nieZ-constraints.ll
@@ -0,0 +1,18 @@
+; RUN: llvm-as < %s | llc -march=x86 | grep {\$-81920} | count 3
+; RUN: llvm-as < %s | llc -march=x86 | grep {\$4294885376} | count 1
+
+; ModuleID = 'shant.c'
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i386-apple-darwin9.6"
+
+define void @f() nounwind {
+entry:
+	call void asm sideeffect "foo $0", "n,~{dirflag},~{fpsr},~{flags}"(i32 -81920) nounwind
+	call void asm sideeffect "foo $0", "i,~{dirflag},~{fpsr},~{flags}"(i32 -81920) nounwind
+	call void asm sideeffect "foo $0", "e,~{dirflag},~{fpsr},~{flags}"(i32 -81920) nounwind
+	call void asm sideeffect "foo $0", "Z,~{dirflag},~{fpsr},~{flags}"(i64 4294885376) nounwind
+	br label %return
+
+return:		; preds = %entry
+	ret void
+}