[llvm-commits] [llvm] r82861 - in /llvm/trunk: lib/CodeGen/SelectionDAG/TargetLowering.cpp test/CodeGen/X86/compare-inf.ll

[Dan Gohman]

Author: djg
Date: Sat Sep 26 10:24:17 2009
New Revision: 82861

URL: http://llvm.org/viewvc/llvm-project?rev=82861&view=rev
Log:
Convert comparisons like (x == infinity) to (x >= infinity) on targets
where FCMP_OEQ is not legal and FCMP_OGE is, such as x86. 

Added:
    llvm/trunk/test/CodeGen/X86/compare-inf.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp?rev=82861&r1=82860&r2=82861&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp Sat Sep 26 10:24:17 2009
@@ -1922,6 +1922,43 @@
     // materialize 0.0.
     if (Cond == ISD::SETO || Cond == ISD::SETUO)
       return DAG.getSetCC(dl, VT, N0, N0, Cond);
+
+    // If the condition is not legal, see if we can find an equivalent one
+    // which is legal.
+    if (!isCondCodeLegal(Cond, N0.getValueType())) {
+      // If the comparison was an awkward floating-point == or != and one of
+      // the comparison operands is infinity or negative infinity, convert the
+      // condition to a less-awkward <= or >=.
+      if (CFP->getValueAPF().isInfinity()) {
+        if (CFP->getValueAPF().isNegative()) {
+          if (Cond == ISD::SETOEQ &&
+              isCondCodeLegal(ISD::SETOLE, N0.getValueType()))
+            return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLE);
+          if (Cond == ISD::SETUEQ &&
+              isCondCodeLegal(ISD::SETOLE, N0.getValueType()))
+            return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULE);
+          if (Cond == ISD::SETUNE &&
+              isCondCodeLegal(ISD::SETUGT, N0.getValueType()))
+            return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGT);
+          if (Cond == ISD::SETONE &&
+              isCondCodeLegal(ISD::SETUGT, N0.getValueType()))
+            return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGT);
+        } else {
+          if (Cond == ISD::SETOEQ &&
+              isCondCodeLegal(ISD::SETOGE, N0.getValueType()))
+            return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGE);
+          if (Cond == ISD::SETUEQ &&
+              isCondCodeLegal(ISD::SETOGE, N0.getValueType()))
+            return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGE);
+          if (Cond == ISD::SETUNE &&
+              isCondCodeLegal(ISD::SETULT, N0.getValueType()))
+            return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULT);
+          if (Cond == ISD::SETONE &&
+              isCondCodeLegal(ISD::SETULT, N0.getValueType()))
+            return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLT);
+        }
+      }
+    }
   }
 
   if (N0 == N1) {

Added: llvm/trunk/test/CodeGen/X86/compare-inf.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/compare-inf.ll?rev=82861&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/compare-inf.ll (added)
+++ llvm/trunk/test/CodeGen/X86/compare-inf.ll Sat Sep 26 10:24:17 2009
@@ -0,0 +1,76 @@
+; RUN: llc < %s -march=x86-64 | FileCheck %s
+
+; Convert oeq and une to ole/oge/ule/uge when comparing with infinity
+; and negative infinity, because those are more efficient on x86.
+
+; CHECK: oeq_inff:
+; CHECK: ucomiss
+; CHECK: jae
+define float @oeq_inff(float %x, float %y) nounwind readonly {
+  %t0 = fcmp oeq float %x, 0x7FF0000000000000
+  %t1 = select i1 %t0, float 1.0, float %y
+  ret float %t1
+}
+
+; CHECK: oeq_inf:
+; CHECK: ucomisd
+; CHECK: jae
+define double @oeq_inf(double %x, double %y) nounwind readonly {
+  %t0 = fcmp oeq double %x, 0x7FF0000000000000
+  %t1 = select i1 %t0, double 1.0, double %y
+  ret double %t1
+}
+
+; CHECK: une_inff:
+; CHECK: ucomiss
+; CHECK: jb
+define float @une_inff(float %x, float %y) nounwind readonly {
+  %t0 = fcmp une float %x, 0x7FF0000000000000
+  %t1 = select i1 %t0, float 1.0, float %y
+  ret float %t1
+}
+
+; CHECK: une_inf:
+; CHECK: ucomisd
+; CHECK: jb
+define double @une_inf(double %x, double %y) nounwind readonly {
+  %t0 = fcmp une double %x, 0x7FF0000000000000
+  %t1 = select i1 %t0, double 1.0, double %y
+  ret double %t1
+}
+
+; CHECK: oeq_neg_inff:
+; CHECK: ucomiss
+; CHECK: jae
+define float @oeq_neg_inff(float %x, float %y) nounwind readonly {
+  %t0 = fcmp oeq float %x, 0xFFF0000000000000
+  %t1 = select i1 %t0, float 1.0, float %y
+  ret float %t1
+}
+
+; CHECK: oeq_neg_inf:
+; CHECK: ucomisd
+; CHECK: jae
+define double @oeq_neg_inf(double %x, double %y) nounwind readonly {
+  %t0 = fcmp oeq double %x, 0xFFF0000000000000
+  %t1 = select i1 %t0, double 1.0, double %y
+  ret double %t1
+}
+
+; CHECK: une_neg_inff:
+; CHECK: ucomiss
+; CHECK: jb
+define float @une_neg_inff(float %x, float %y) nounwind readonly {
+  %t0 = fcmp une float %x, 0xFFF0000000000000
+  %t1 = select i1 %t0, float 1.0, float %y
+  ret float %t1
+}
+
+; CHECK: une_neg_inf:
+; CHECK: ucomisd
+; CHECK: jb
+define double @une_neg_inf(double %x, double %y) nounwind readonly {
+  %t0 = fcmp une double %x, 0xFFF0000000000000
+  %t1 = select i1 %t0, double 1.0, double %y
+  ret double %t1
+}