[AMDGPU][MC] Fix for Bugs 28200, 28202 + LIT tests

Fixed several related issues with VOP3 fp modifiers.

Reviewers: artem.tamazov

Differential Revision: https://reviews.llvm.org/D30821

llvm-svn: 298255

1 files changed, 23 insertions, 2 deletions

diff --git a/llvm/lib/Target/AMDGPU/InstPrinter/AMDGPUInstPrinter.cpp b/llvm/lib/Target/AMDGPU/InstPrinter/AMDGPUInstPrinter.cpp
index 202850664db..8d04f834dd9 100644
--- a/llvm/lib/Target/AMDGPU/InstPrinter/AMDGPUInstPrinter.cpp
+++ b/llvm/lib/Target/AMDGPU/InstPrinter/AMDGPUInstPrinter.cpp
@@ -543,13 +543,34 @@ void AMDGPUInstPrinter::printOperandAndFPInputMods(const MCInst *MI,
                                                    const MCSubtargetInfo &STI,
                                                    raw_ostream &O) {
   unsigned InputModifiers = MI->getOperand(OpNo).getImm();
-  if (InputModifiers & SISrcMods::NEG)
-    O << '-';
+
+  // Use 'neg(...)' instead of '-' to avoid ambiguity.
+  // This is important for integer literals because
+  // -1 is not the same value as neg(1).
+  bool NegMnemo = false;
+
+  if (InputModifiers & SISrcMods::NEG) {
+    if (OpNo + 1 < MI->getNumOperands() &&
+        (InputModifiers & SISrcMods::ABS) == 0) {
+      const MCOperand &Op = MI->getOperand(OpNo + 1);
+      NegMnemo = Op.isImm() || Op.isFPImm();
+    }
+    if (NegMnemo) {
+      O << "neg(";
+    } else {
+      O << '-';
+    }
+  }
+
   if (InputModifiers & SISrcMods::ABS)
     O << '|';
   printOperand(MI, OpNo + 1, STI, O);
   if (InputModifiers & SISrcMods::ABS)
     O << '|';
+
+  if (NegMnemo) {
+    O << ')';
+  }
 }
 
 void AMDGPUInstPrinter::printOperandAndIntInputMods(const MCInst *MI,