Change this DAGCombine to build AND of SHR instead of SHR of AND; this matches the ordering we prefer in instcombine. Part of rdar://9562809.

The potential DAGCombine which enforces this more generally messes up some other very fragile patterns, so I'm leaving that alone, at least for now.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132809 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/X86/shift-pair.ll

@@ -0,0 +1,11 @@
+; RUN: llc < %s -march=x86-64 | FileCheck %s
+
+define i64 @test(i64 %A) {
+; CHECK: @test
+; CHECK: shrq $54
+; CHECK: andq $1020
+; CHECK: ret
+    %B = lshr i64 %A, 56
+    %C = shl i64 %B, 2
+    ret i64 %C
+}