Add combiner patterns to more effectively utilize the BFI (bitfield insert)

instruction for non-constant operands. This includes the case referenced
in the README.txt regarding a bitfield copy.

llvm-svn: 108608

1 files changed, 23 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/ARM/bfi.ll b/llvm/test/CodeGen/ARM/bfi.ll
index 48ef43762f0..59e2b43a917 100644
--- a/llvm/test/CodeGen/ARM/bfi.ll
+++ b/llvm/test/CodeGen/ARM/bfi.ll
@@ -15,3 +15,26 @@ entry:
   store i32 %2, i32* bitcast (%struct.F* @X to i32*), align 4
   ret void
 }
+
+define i32 @f2(i32 %A, i32 %B) nounwind readnone optsize {
+entry:
+; CHECK: f2
+; CHECK: mov r1, r1, lsr #7
+; CHECK: bfi r0, r1, #7, #16
+  %and = and i32 %A, -8388481                     ; <i32> [#uses=1]
+  %and2 = and i32 %B, 8388480                     ; <i32> [#uses=1]
+  %or = or i32 %and2, %and                        ; <i32> [#uses=1]
+  ret i32 %or
+}
+
+define i32 @f3(i32 %A, i32 %B) nounwind readnone optsize {
+entry:
+; CHECK: f3
+; CHECK: mov r2, r0, lsr #7
+; CHECK: mov r0, r1
+; CHECK: bfi r0, r2, #7, #16
+  %and = and i32 %A, 8388480                      ; <i32> [#uses=1]
+  %and2 = and i32 %B, -8388481                    ; <i32> [#uses=1]
+  %or = or i32 %and2, %and                        ; <i32> [#uses=1]
+  ret i32 %or
+}