Make the canonicalisation on shifts benifit to more case.

1.Fix pessimized case in FIXME.
2.Add tests for it.
3.The canonicalisation on shifts results in different sequence for
  tests of machine-licm.Correct some check lines.

Differential Revision: https://reviews.llvm.org/D27916

llvm-svn: 290410

1 files changed, 31 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/ARM/shift-combine.ll b/llvm/test/CodeGen/ARM/shift-combine.ll
new file mode 100644
index 00000000000..9da3b31b9a1
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/shift-combine.ll
@@ -0,0 +1,31 @@
+; RUN: llc -mtriple=armv7-linux-gnueabihf %s -o - | FileCheck %s
+
+@array = weak global [4 x i32] zeroinitializer
+
+define i32 @test_lshr_and1(i32 %x) {
+entry:
+;CHECK-LABLE: test_lshr_and1:
+;CHECK:         movw r1, :lower16:array
+;CHECK-NEXT:    and  r0, r0, #12
+;CHECK-NEXT:    movt r1, :upper16:array
+;CHECK-NEXT:    ldr  r0, [r1, r0]
+;CHECK-NEXT:    bx   lr
+  %tmp2 = lshr i32 %x, 2
+  %tmp3 = and i32 %tmp2, 3
+  %tmp4 = getelementptr [4 x i32], [4 x i32]* @array, i32 0, i32 %tmp3
+  %tmp5 = load i32, i32* %tmp4, align 4
+  ret i32 %tmp5
+}
+define i32 @test_lshr_and2(i32 %x) {
+entry:
+;CHECK-LABLE: test_lshr_and2:
+;CHECK:         ubfx r0, r0, #1, #15
+;CHECK-NEXT:    add  r0, r0, r0
+;CHECK-NEXT:    bx   lr
+  %a = and i32 %x, 65534
+  %b = lshr i32 %a, 1
+  %c = and i32 %x, 65535
+  %d = lshr i32 %c, 1
+  %e = add i32 %b, %d
+  ret i32 %e
+}