[llvm] AMDGPU: Fix packed 16-bit inline constants (PR #76522)

[Stanislav Mekhanoshin via llvm-commits]

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@@ -460,56 +460,84 @@ void AMDGPUInstPrinter::printImmediateInt16(uint32_t Imm,
   }
 }
 
-void AMDGPUInstPrinter::printImmediate16(uint32_t Imm,
-                                         const MCSubtargetInfo &STI,
-                                         raw_ostream &O) {
-  int16_t SImm = static_cast<int16_t>(Imm);
-  if (isInlinableIntLiteral(SImm)) {
-    O << SImm;
-    return;
-  }
-
+// This must accept a 32-bit immediate value to correctly handle packed 16-bit
+// operations.
+static bool printImmediateFloat16(uint32_t Imm, const MCSubtargetInfo &STI,
+                                  raw_ostream &O) {
   if (Imm == 0x3C00)
-    O<< "1.0";
+    O << "1.0";
   else if (Imm == 0xBC00)
-    O<< "-1.0";
+    O << "-1.0";
   else if (Imm == 0x3800)
-    O<< "0.5";
+    O << "0.5";
   else if (Imm == 0xB800)
-    O<< "-0.5";
+    O << "-0.5";
   else if (Imm == 0x4000)
-    O<< "2.0";
+    O << "2.0";
   else if (Imm == 0xC000)
-    O<< "-2.0";
+    O << "-2.0";
   else if (Imm == 0x4400)
-    O<< "4.0";
+    O << "4.0";
   else if (Imm == 0xC400)
-    O<< "-4.0";
-  else if (Imm == 0x3118 &&
-           STI.hasFeature(AMDGPU::FeatureInv2PiInlineImm)) {
+    O << "-4.0";
+  else if (Imm == 0x3118 && STI.hasFeature(AMDGPU::FeatureInv2PiInlineImm))
     O << "0.15915494";
-  } else {
-    uint64_t Imm16 = static_cast<uint16_t>(Imm);
-    O << formatHex(Imm16);
-  }
-}
+  else
+    return false;
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rampitec wrote:

Why not just print it here and not handle it in both places below?

https://github.com/llvm/llvm-project/pull/76522