[llvm-commits] [llvm] r136787 - in /llvm/trunk: lib/Target/X86/X86FloatingPoint.cpp test/CodeGen/X86/fp-stack-O0-crash.ll

[Jakob Stoklund Olesen]

Author: stoklund
Date: Wed Aug  3 11:33:19 2011
New Revision: 136787

URL: http://llvm.org/viewvc/llvm-project?rev=136787&view=rev
Log:
Handle IMPLICIT_DEF instructions in X86FloatingPoint.

This fixes PR10575.

Modified:
    llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp
    llvm/trunk/test/CodeGen/X86/fp-stack-O0-crash.ll

Modified: llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp?rev=136787&r1=136786&r2=136787&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp Wed Aug  3 11:33:19 2011
@@ -406,6 +406,10 @@
     if (MI->isCopy() && isFPCopy(MI))
       FPInstClass = X86II::SpecialFP;
 
+    if (MI->isImplicitDef() &&
+        X86::RFP80RegClass.contains(MI->getOperand(0).getReg()))
+      FPInstClass = X86II::SpecialFP;
+
     if (FPInstClass == X86II::NotFP)
       continue;  // Efficiently ignore non-fp insts!
 
@@ -1369,6 +1373,15 @@
     break;
   }
 
+  case TargetOpcode::IMPLICIT_DEF: {
+    // All FP registers must be explicitly defined, so load a 0 instead.
+    unsigned Reg = MI->getOperand(0).getReg() - X86::FP0;
+    DEBUG(dbgs() << "Emitting LD_F0 for implicit FP" << Reg << '\n');
+    BuildMI(*MBB, I, MI->getDebugLoc(), TII->get(X86::LD_F0));
+    pushReg(Reg);
+    break;
+  }
+
   case X86::FpPOP_RETVAL: {
     // The FpPOP_RETVAL instruction is used after calls that return a value on
     // the floating point stack. We cannot model this with ST defs since CALL

Modified: llvm/trunk/test/CodeGen/X86/fp-stack-O0-crash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fp-stack-O0-crash.ll?rev=136787&r1=136786&r2=136787&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/fp-stack-O0-crash.ll (original)
+++ llvm/trunk/test/CodeGen/X86/fp-stack-O0-crash.ll Wed Aug  3 11:33:19 2011
@@ -1,4 +1,4 @@
-; RUN: llc %s -O0 -fast-isel -regalloc=fast -o -
+; RUN: llc %s -O0 -fast-isel -regalloc=fast -mcpu=i386 -o -
 ; PR4767
 
 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"
@@ -28,3 +28,22 @@
 if.end:                                           ; preds = %if.then, %cond.false, %cond.true
   ret void
 }
+
+; PR10575
+; This produces a FP0 = IMPLICIT_DEF instruction.
+define void @__m_rankmerge_MOD_dindexmerge_() nounwind {
+entry:
+  br label %"20"
+
+"20":                                             ; preds = %"23", %entry
+    %0 = phi double [ undef, %entry ], [ %0, %"23" ]
+    %1 = phi double [ 0.000000e+00, %entry ], [ %2, %"23" ]
+    br i1 undef, label %"21", label %"23"
+
+"21":                                             ; preds = %"20"
+    ret void
+
+"23":                                             ; preds = %"20"
+    %2 = select i1 undef, double %0, double %1
+    br label %"20"
+}