Don't try to replace physical registers when doing CSE.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97360 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/MachineLICM.cpp b/lib/CodeGen/MachineLICM.cpp
index 5580ec13f4ff6ecc74d69c4f69dbe3d2f11d0071..bb80cd67ce51e7663dac237bb0152bb5356c8389 100644 (file)
--- a/lib/CodeGen/MachineLICM.cpp
+++ b/lib/CodeGen/MachineLICM.cpp
@@ -458,9 +458,20 @@ bool MachineLICM::EliminateCSE(MachineInstr *MI,
 
   if (const MachineInstr *Dup = LookForDuplicate(MI, CI->second)) {
     DEBUG(dbgs() << "CSEing " << *MI << " with " << *Dup);
+
+    // Replace virtual registers defined by MI by their counterparts defined
+    // by Dup.
     for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
       const MachineOperand &MO = MI->getOperand(i);
-      if (MO.isReg() && MO.isDef())
+
+      // Physical registers may not differ here.
+      assert((!MO.isReg() || MO.getReg() == 0 ||
+              !TargetRegisterInfo::isPhysicalRegister(MO.getReg()) ||
+              MO.getReg() == Dup->getOperand(i).getReg()) &&
+             "Instructions with different phys regs are not identical!");
+
+      if (MO.isReg() && MO.isDef() &&
+          !TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
         RegInfo->replaceRegWith(MO.getReg(), Dup->getOperand(i).getReg());
     }
     MI->eraseFromParent();

diff --git a/test/CodeGen/X86/licm-symbol.ll b/test/CodeGen/X86/licm-symbol.ll
new file mode 100644 (file)
index 0000000..d61bbfc
--- /dev/null
+++ b/test/CodeGen/X86/licm-symbol.ll
@@ -0,0 +1,39 @@
+; RUN: llc < %s | FileCheck %s
+
+; MachineLICM should be able to hoist the sF reference out of the loop.
+
+; CHECK: pushl %esi
+; CHECK: subl  $8, %esp
+; CHECK: movl  $176, %esi
+; CHECK: addl  L___sF$non_lazy_ptr, %esi
+; CHECK: .align  4, 0x90
+
+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-n8:16:32"
+target triple = "i386-apple-darwin8"
+
+%struct.FILE = type { i8*, i32, i32, i16, i16, %struct.__sbuf, i32, i8*, i32 (i8*)*, i32 (i8*, i8*, i32)*, i64 (i8*, i64, i32)*, i32 (i8*, i8*, i32)*, %struct.__sbuf, %struct.__sFILEX*, i32, [3 x i8], [1 x i8], %struct.__sbuf, i32, i64 }
+%struct.__sFILEX = type opaque
+%struct.__sbuf = type { i8*, i32 }
+%struct.gcov_ctr_summary = type { i32, i32, i64, i64, i64 }
+%struct.gcov_summary = type { i32, [1 x %struct.gcov_ctr_summary] }
+
+@__sF = external global [0 x %struct.FILE]        ; <[0 x %struct.FILE]*> [#uses=1]
+
+declare i32 @fprintf(%struct.FILE* nocapture) nounwind
+
+define void @gcov_exit() nounwind {
+entry:
+  br label %bb151
+
+bb151:                                            ; preds = %bb59, %bb56, %bb14
+  br i1 undef, label %bb56, label %bb59
+
+bb56:                                             ; preds = %bb151
+  %t0 = call i32 (%struct.FILE*)* @fprintf(%struct.FILE* getelementptr inbounds ([0 x %struct.FILE]* @__sF, i32 0, i32 2)) nounwind
+  br label %bb151
+
+bb59:                                             ; preds = %bb151
+  %t1 = call i32 (%struct.FILE*)* @fprintf(%struct.FILE* getelementptr inbounds ([0 x %struct.FILE]* @__sF, i32 0, i32 2)) nounwind
+  br label %bb151
+}
+