Fix a obvious logic error.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82610 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 139 insertions, 15 deletions

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 22b62c3603..a1b6adc9e4 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -826,21 +826,21 @@ void SimpleRegisterCoalescing::RemoveUnnecessaryKills(unsigned Reg,
     MachineInstrIndex UseIdx =
       li_->getUseIndex(li_->getInstructionIndex(UseMI));
     const LiveRange *LR = LI.getLiveRangeContaining(UseIdx);
-    if (!LR || !LR->valno->isKill(li_->getNextSlot(UseIdx))) {
-      if (LR->valno->def != li_->getNextSlot(UseIdx)) {
-        // Interesting problem. After coalescing reg1027's def and kill are both
-        // at the same point:  %reg1027,0.000000e+00 = [56,814:0)  0@70-(814)
-        //
-        // bb5:
-        // 60   %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
-        // 68   %reg1027<def> = t2LDRi12 %reg1027<kill>, 8, 14, %reg0
-        // 76   t2CMPzri %reg1038<kill,undef>, 0, 14, %reg0, %CPSR<imp-def>
-        // 84   %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
-        // 96   t2Bcc mbb<bb5,0x2030910>, 1, %CPSR<kill>
-        //
-        // Do not remove the kill marker on t2LDRi12.
-        UseMO.setIsKill(false);
-      }
+    if (!LR ||
+        (!LR->valno->isKill(li_->getNextSlot(UseIdx)) &&
+         LR->valno->def != li_->getNextSlot(UseIdx))) {
+      // Interesting problem. After coalescing reg1027's def and kill are both
+      // at the same point:  %reg1027,0.000000e+00 = [56,814:0)  0@70-(814)
+      //
+      // bb5:
+      // 60   %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
+      // 68   %reg1027<def> = t2LDRi12 %reg1027<kill>, 8, 14, %reg0
+      // 76   t2CMPzri %reg1038<kill,undef>, 0, 14, %reg0, %CPSR<imp-def>
+      // 84   %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
+      // 96   t2Bcc mbb<bb5,0x2030910>, 1, %CPSR<kill>
+      //
+      // Do not remove the kill marker on t2LDRi12.
+      UseMO.setIsKill(false);
     }
   }
 }
diff --git a/test/CodeGen/X86/2009-09-22-CoalescerBug.ll b/test/CodeGen/X86/2009-09-22-CoalescerBug.ll
new file mode 100644
index 0000000000..33f35f881e
--- /dev/null
+++ b/test/CodeGen/X86/2009-09-22-CoalescerBug.ll
@@ -0,0 +1,124 @@
+; RUN: llc < %s -mtriple=x86_64-apple-darwin10
+
+define i32 @main(i32 %argc, i8** nocapture %argv) nounwind ssp {
+entry:
+  br i1 undef, label %bb, label %bb1
+
+bb:                                               ; preds = %entry
+  ret i32 3
+
+bb1:                                              ; preds = %entry
+  br i1 undef, label %bb3, label %bb2
+
+bb2:                                              ; preds = %bb1
+  ret i32 3
+
+bb3:                                              ; preds = %bb1
+  br i1 undef, label %bb.i18, label %quantum_getwidth.exit
+
+bb.i18:                                           ; preds = %bb.i18, %bb3
+  br i1 undef, label %bb.i18, label %quantum_getwidth.exit
+
+quantum_getwidth.exit:                            ; preds = %bb.i18, %bb3
+  br i1 undef, label %bb4, label %bb6.preheader
+
+bb4:                                              ; preds = %quantum_getwidth.exit
+  unreachable
+
+bb6.preheader:                                    ; preds = %quantum_getwidth.exit
+  br i1 undef, label %bb.i1, label %bb1.i2
+
+bb.i1:                                            ; preds = %bb6.preheader
+  unreachable
+
+bb1.i2:                                           ; preds = %bb6.preheader
+  br i1 undef, label %bb2.i, label %bb3.i4
+
+bb2.i:                                            ; preds = %bb1.i2
+  unreachable
+
+bb3.i4:                                           ; preds = %bb1.i2
+  br i1 undef, label %quantum_new_qureg.exit, label %bb4.i
+
+bb4.i:                                            ; preds = %bb3.i4
+  unreachable
+
+quantum_new_qureg.exit:                           ; preds = %bb3.i4
+  br i1 undef, label %bb9, label %bb11.thread
+
+bb11.thread:                                      ; preds = %quantum_new_qureg.exit
+  %.cast.i = zext i32 undef to i64                ; <i64> [#uses=1]
+  br label %bb.i37
+
+bb9:                                              ; preds = %quantum_new_qureg.exit
+  unreachable
+
+bb.i37:                                           ; preds = %bb.i37, %bb11.thread
+  %0 = load i64* undef, align 8                   ; <i64> [#uses=1]
+  %1 = shl i64 %0, %.cast.i                       ; <i64> [#uses=1]
+  store i64 %1, i64* undef, align 8
+  br i1 undef, label %bb.i37, label %quantum_addscratch.exit
+
+quantum_addscratch.exit:                          ; preds = %bb.i37
+  br i1 undef, label %bb12.preheader, label %bb14
+
+bb12.preheader:                                   ; preds = %quantum_addscratch.exit
+  unreachable
+
+bb14:                                             ; preds = %quantum_addscratch.exit
+  br i1 undef, label %bb17, label %bb.nph
+
+bb.nph:                                           ; preds = %bb14
+  unreachable
+
+bb17:                                             ; preds = %bb14
+  br i1 undef, label %bb1.i7, label %quantum_measure.exit
+
+bb1.i7:                                           ; preds = %bb17
+  br label %quantum_measure.exit
+
+quantum_measure.exit:                             ; preds = %bb1.i7, %bb17
+  switch i32 undef, label %bb21 [
+    i32 -1, label %bb18
+    i32 0, label %bb20
+  ]
+
+bb18:                                             ; preds = %quantum_measure.exit
+  unreachable
+
+bb20:                                             ; preds = %quantum_measure.exit
+  unreachable
+
+bb21:                                             ; preds = %quantum_measure.exit
+  br i1 undef, label %quantum_frac_approx.exit, label %bb1.i
+
+bb1.i:                                            ; preds = %bb21
+  unreachable
+
+quantum_frac_approx.exit:                         ; preds = %bb21
+  br i1 undef, label %bb25, label %bb26
+
+bb25:                                             ; preds = %quantum_frac_approx.exit
+  unreachable
+
+bb26:                                             ; preds = %quantum_frac_approx.exit
+  br i1 undef, label %quantum_gcd.exit, label %bb.i
+
+bb.i:                                             ; preds = %bb.i, %bb26
+  br i1 undef, label %quantum_gcd.exit, label %bb.i
+
+quantum_gcd.exit:                                 ; preds = %bb.i, %bb26
+  br i1 undef, label %bb32, label %bb33
+
+bb32:                                             ; preds = %quantum_gcd.exit
+  br i1 undef, label %bb.i.i, label %quantum_delete_qureg.exit
+
+bb.i.i:                                           ; preds = %bb32
+  ret i32 0
+
+quantum_delete_qureg.exit:                        ; preds = %bb32
+  ret i32 0
+
+bb33:                                             ; preds = %quantum_gcd.exit
+  unreachable
+}