Index: lib/Target/X86/X86InstrInfo.td
===================================================================
--- lib/Target/X86/X86InstrInfo.td
+++ lib/Target/X86/X86InstrInfo.td
@@ -2429,6 +2429,7 @@
 }
 
 let Predicates = [HasBMI2] in {
+  // x & ((1 << y) + (-1))
   def : Pat<(and GR32:$src, (add (shl 1, GR8:$lz), -1)),
             (BZHI32rr GR32:$src,
               (INSERT_SUBREG (i32 (IMPLICIT_DEF)), GR8:$lz, sub_8bit))>;
@@ -2445,6 +2446,12 @@
             (BZHI64rm addr:$src,
               (INSERT_SUBREG (i64 (IMPLICIT_DEF)), GR8:$lz, sub_8bit))>;
 
+  // x & ~(-1 << y)
+  def : Pat<(and GR32:$src, (xor(shl -1, (i8 (trunc GR32:$lz))), -1)),
+            (BZHI32rr GR32:$src, GR32:$lz)>;
+  def : Pat<(and (loadi32 addr:$src), (xor(shl -1, (i8 (trunc GR32:$lz))), -1)),
+            (BZHI32rm addr:$src, GR32:$lz)>;
+
   // x & (-1 >> (32 - y))
   def : Pat<(and GR32:$src, (srl -1, (i8 (trunc (sub 32, GR32:$lz))))),
             (BZHI32rr GR32:$src, GR32:$lz)>;
Index: test/CodeGen/X86/get-lowbits.ll
===================================================================
--- test/CodeGen/X86/get-lowbits.ll
+++ test/CodeGen/X86/get-lowbits.ll
@@ -34,9 +34,7 @@
 ;
 ; CHECK-BMI2-LABEL: test0:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $al killed $al killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = zext i16 %nbits to i32
@@ -103,9 +101,7 @@
 ;
 ; CHECK-BMI2-LABEL: test2:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $al killed $al killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = shl i32 -1, %nbits
@@ -170,9 +166,7 @@
 ;
 ; CHECK-BMI2-LABEL: test4:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $al killed $al killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = zext i8 %nbits to i32
@@ -239,9 +233,7 @@
 ;
 ; CHECK-BMI2-LABEL: test6:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $al killed $al killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = trunc i64 %val to i32
@@ -310,9 +302,7 @@
 ;
 ; CHECK-BMI2-LABEL: test8:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $al killed $al killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = trunc i64 %val to i32
@@ -449,9 +439,7 @@
 ;
 ; CHECK-BMI2-LABEL: test12:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $al killed $al killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = trunc i64 %val to i32
@@ -520,9 +508,7 @@
 ;
 ; CHECK-BMI2-LABEL: test14:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $al killed $al killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = zext i8 %nbits to i32
@@ -591,9 +577,7 @@
 ;
 ; CHECK-BMI2-LABEL: test16:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $ax killed $ax killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = zext i16 %nbits to i32
@@ -660,9 +644,7 @@
 ;
 ; CHECK-BMI2-LABEL: test18:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $ax killed $ax killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = shl i32 -1, %nbits
@@ -727,9 +709,7 @@
 ;
 ; CHECK-BMI2-LABEL: test20:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $ax killed $ax killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = zext i8 %nbits to i32
@@ -796,9 +776,7 @@
 ;
 ; CHECK-BMI2-LABEL: test22:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $ax killed $ax killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = trunc i64 %val to i32
@@ -867,9 +845,7 @@
 ;
 ; CHECK-BMI2-LABEL: test24:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $ax killed $ax killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = trunc i64 %val to i32
@@ -1006,9 +982,7 @@
 ;
 ; CHECK-BMI2-LABEL: test28:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $ax killed $ax killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = trunc i64 %val to i32
@@ -1077,9 +1051,7 @@
 ;
 ; CHECK-BMI2-LABEL: test30:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    # kill: def $ax killed $ax killed $eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = zext i8 %nbits to i32
@@ -1146,9 +1118,7 @@
 ;
 ; CHECK-BMI2-LABEL: test32:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = shl i32 -1, %nbits
   %tmp2 = xor i32 %tmp, -1
@@ -1205,9 +1175,7 @@
 ;
 ; CHECK-BMI2-LABEL: test34:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = zext i8 %nbits to i32
   %tmp2 = shl i32 -1, %tmp
@@ -1266,9 +1234,7 @@
 ;
 ; CHECK-BMI2-LABEL: test36:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = trunc i64 %val to i32
   %tmp2 = shl i32 -1, %nbits
@@ -1395,9 +1361,7 @@
 ;
 ; CHECK-BMI2-LABEL: test40:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = trunc i64 %val to i32
   %tmp2 = zext i8 %nbits to i32
@@ -1458,9 +1422,7 @@
 ;
 ; CHECK-BMI2-LABEL: test42:
 ; CHECK-BMI2:       # %bb.0:
-; CHECK-BMI2-NEXT:    movl $-1, %eax
-; CHECK-BMI2-NEXT:    shlxl %esi, %eax, %eax
-; CHECK-BMI2-NEXT:    andnl %edi, %eax, %eax
+; CHECK-BMI2-NEXT:    bzhil %esi, %edi, %eax
 ; CHECK-BMI2-NEXT:    retq
   %tmp = zext i8 %nbits to i32
   %tmp2 = shl i32 -1, %tmp