JDK-8171092 : C1's Math.fma() intrinsic doesn't correctly process its inputs
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 9
  • Priority: P3
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2016-12-12
  • Updated: 2017-01-05
  • Resolved: 2016-12-19
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JDK 9
9 b151Fixed
Related Reports
Relates :  
JDK-8162338 - AArch64: Intrinsify fused mac operations
Description
3rd input of Math.fma() is processed as a temp not as an input:

diff --git a/src/share/vm/c1/c1_LIR.cpp b/src/share/vm/c1/c1_LIR.cpp
--- a/src/share/vm/c1/c1_LIR.cpp
+++ b/src/share/vm/c1/c1_LIR.cpp
@@ -677,9 +677,7 @@
 
 // LIR_Op3
     case lir_idiv:
-    case lir_irem:
-    case lir_fmad:
-    case lir_fmaf: {
+    case lir_irem: {
       assert(op->as_Op3() != NULL, "must be");
       LIR_Op3* op3= (LIR_Op3*)op;
 
@@ -697,6 +695,17 @@
       break;
     }
 
+    case lir_fmad:
+    case lir_fmaf: {
+      assert(op->as_Op3() != NULL, "must be");
+      LIR_Op3* op3= (LIR_Op3*)op;
+      assert(op3->_info == NULL, "no info");
+      do_input(op3->_opr1);
+      do_input(op3->_opr2);
+      do_input(op3->_opr3);
+      do_output(op3->_result);
+      break;
+    }
 
 // LIR_OpJavaCall
     case lir_static_call: