Index: llvm/trunk/lib/Target/X86/X86VZeroUpper.cpp
===================================================================
--- llvm/trunk/lib/Target/X86/X86VZeroUpper.cpp
+++ llvm/trunk/lib/Target/X86/X86VZeroUpper.cpp
@@ -192,6 +192,12 @@
     if ((!IsControlFlow || IsReturnFromX86INTR) && CurState == EXITS_DIRTY)
       continue;
 
+    // Ignore existing VZERO* instructions.
+    // FIXME: The existence of these instructions should be used to modify the
+    // current state and/or used when deciding whether we need to create a VZU.
+    if (MI->getOpcode() == X86::VZEROALL || MI->getOpcode() == X86::VZEROUPPER)
+      continue;
+
     if (hasYmmReg(MI)) {
       // We found a ymm-using instruction; this could be an AVX instruction,
       // or it could be control flow.
Index: llvm/trunk/test/CodeGen/X86/avx-intrinsics-fast-isel.ll
===================================================================
--- llvm/trunk/test/CodeGen/X86/avx-intrinsics-fast-isel.ll
+++ llvm/trunk/test/CodeGen/X86/avx-intrinsics-fast-isel.ll
@@ -3736,13 +3736,11 @@
 ; X32-LABEL: test_mm256_zeroall:
 ; X32:       # BB#0:
 ; X32-NEXT:    vzeroall
-; X32-NEXT:    vzeroupper
 ; X32-NEXT:    retl
 ;
 ; X64-LABEL: test_mm256_zeroall:
 ; X64:       # BB#0:
 ; X64-NEXT:    vzeroall
-; X64-NEXT:    vzeroupper
 ; X64-NEXT:    retq
   call void @llvm.x86.avx.vzeroall()
   ret void
@@ -3753,13 +3751,11 @@
 ; X32-LABEL: test_mm256_zeroupper:
 ; X32:       # BB#0:
 ; X32-NEXT:    vzeroupper
-; X32-NEXT:    vzeroupper
 ; X32-NEXT:    retl
 ;
 ; X64-LABEL: test_mm256_zeroupper:
 ; X64:       # BB#0:
 ; X64-NEXT:    vzeroupper
-; X64-NEXT:    vzeroupper
 ; X64-NEXT:    retq
   call void @llvm.x86.avx.vzeroupper()
   ret void
Index: llvm/trunk/test/CodeGen/X86/avx-intrinsics-x86.ll
===================================================================
--- llvm/trunk/test/CodeGen/X86/avx-intrinsics-x86.ll
+++ llvm/trunk/test/CodeGen/X86/avx-intrinsics-x86.ll
@@ -4755,7 +4755,6 @@
 ; AVX-LABEL: test_x86_avx_vzeroall:
 ; AVX:       ## BB#0:
 ; AVX-NEXT:    vzeroall
-; AVX-NEXT:    vzeroupper
 ; AVX-NEXT:    retl
 ;
 ; AVX512VL-LABEL: test_x86_avx_vzeroall:
@@ -4772,7 +4771,6 @@
 ; AVX-LABEL: test_x86_avx_vzeroupper:
 ; AVX:       ## BB#0:
 ; AVX-NEXT:    vzeroupper
-; AVX-NEXT:    vzeroupper
 ; AVX-NEXT:    retl
 ;
 ; AVX512VL-LABEL: test_x86_avx_vzeroupper: