Fix a thinko in post-allocation coalescer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44166 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 833868a458561e89f73eebdf6bfd2fc789a9c088..55094e3e5d6347d064e16d31679e80e4dc81c5e5 100644 (file)
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -168,15 +168,22 @@ bool LiveIntervals::conflictsWithPhysRegDef(const LiveInterval &li,
       if (index == end) break;
 
       MachineInstr *MI = getInstructionFromIndex(index);
+      unsigned SrcReg, DstReg;
+      if (tii_->isMoveInstr(*MI, SrcReg, DstReg))
+        if (SrcReg == li.reg || DstReg == li.reg)
+          continue;
       for (unsigned i = 0; i != MI->getNumOperands(); ++i) {
         MachineOperand& mop = MI->getOperand(i);
-        if (!mop.isRegister() || !mop.isDef())
+        if (!mop.isRegister())
           continue;
         unsigned PhysReg = mop.getReg();
-        if (PhysReg == 0)
+        if (PhysReg == 0 || PhysReg == li.reg)
           continue;
-        if (MRegisterInfo::isVirtualRegister(PhysReg))
+        if (MRegisterInfo::isVirtualRegister(PhysReg)) {
+          if (!vrm.hasPhys(PhysReg))
+            continue;
           PhysReg = vrm.getPhys(PhysReg);
+        }
         if (PhysReg && mri_->regsOverlap(PhysReg, reg))
           return true;
       }

diff --git a/test/CodeGen/X86/2007-11-14-Coalescer-Bug.ll b/test/CodeGen/X86/2007-11-14-Coalescer-Bug.ll
new file mode 100644 (file)
index 0000000..4a8f376
--- /dev/null
+++ b/test/CodeGen/X86/2007-11-14-Coalescer-Bug.ll
@@ -0,0 +1,67 @@
+; RUN: llvm-as < %s | llc -march=x86 -x86-asm-syntax=att | grep movl | grep 4
+
+       %struct.double_int = type { i64, i64 }
+       %struct.tree_common = type <{ i8, [3 x i8] }>
+       %struct.tree_int_cst = type { %struct.tree_common, %struct.double_int }
+       %struct.tree_node = type { %struct.tree_int_cst }
+@tree_code_type = external constant [0 x i32]          ; <[0 x i32]*> [#uses=1]
+
+define i32 @simple_cst_equal(%struct.tree_node* %t1, %struct.tree_node* %t2) {
+entry:
+       %tmp2526 = bitcast %struct.tree_node* %t1 to i32*               ; <i32*> [#uses=1]
+       br i1 false, label %UnifiedReturnBlock, label %bb21
+
+bb21:          ; preds = %entry
+       %tmp27 = load i32* %tmp2526, align 4            ; <i32> [#uses=1]
+       %tmp29 = and i32 %tmp27, 255            ; <i32> [#uses=3]
+       %tmp2930 = trunc i32 %tmp29 to i8               ; <i8> [#uses=1]
+       %tmp37 = load i32* null, align 4                ; <i32> [#uses=1]
+       %tmp39 = and i32 %tmp37, 255            ; <i32> [#uses=2]
+       %tmp3940 = trunc i32 %tmp39 to i8               ; <i8> [#uses=1]
+       %tmp43 = add i32 %tmp29, -3             ; <i32> [#uses=1]
+       %tmp44 = icmp ult i32 %tmp43, 3         ; <i1> [#uses=1]
+       br i1 %tmp44, label %bb47.split, label %bb76
+
+bb47.split:            ; preds = %bb21
+       ret i32 0
+
+bb76:          ; preds = %bb21
+       br i1 false, label %bb82, label %bb146.split
+
+bb82:          ; preds = %bb76
+       %tmp94 = getelementptr [0 x i32]* @tree_code_type, i32 0, i32 %tmp39            ; <i32*> [#uses=1]
+       %tmp95 = load i32* %tmp94, align 4              ; <i32> [#uses=1]
+       %tmp9596 = trunc i32 %tmp95 to i8               ; <i8> [#uses=1]
+       %tmp98 = add i8 %tmp9596, -4            ; <i8> [#uses=1]
+       %tmp99 = icmp ugt i8 %tmp98, 5          ; <i1> [#uses=1]
+       br i1 %tmp99, label %bb102, label %bb106
+
+bb102:         ; preds = %bb82
+       ret i32 0
+
+bb106:         ; preds = %bb82
+       ret i32 0
+
+bb146.split:           ; preds = %bb76
+       %tmp149 = icmp eq i8 %tmp2930, %tmp3940         ; <i1> [#uses=1]
+       br i1 %tmp149, label %bb153, label %UnifiedReturnBlock
+
+bb153:         ; preds = %bb146.split
+       switch i32 %tmp29, label %UnifiedReturnBlock [
+                i32 0, label %bb155
+                i32 1, label %bb187
+       ]
+
+bb155:         ; preds = %bb153
+       ret i32 0
+
+bb187:         ; preds = %bb153
+       %tmp198 = icmp eq %struct.tree_node* %t1, %t2           ; <i1> [#uses=1]
+       br i1 %tmp198, label %bb201, label %UnifiedReturnBlock
+
+bb201:         ; preds = %bb187
+       ret i32 0
+
+UnifiedReturnBlock:            ; preds = %bb187, %bb153, %bb146.split, %entry
+       ret i32 0
+}