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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108608 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 21 deletions

diff --git a/lib/Target/ARM/README.txt b/lib/Target/ARM/README.txt
index 0cb8ff0118..ba4e5da5a0 100644
--- a/lib/Target/ARM/README.txt
+++ b/lib/Target/ARM/README.txt
@@ -611,27 +611,6 @@ constant which was already loaded).  Not sure what's necessary to do that.
 
 //===---------------------------------------------------------------------===//
 
-Given the following on ARMv7:
-int test1(int A, int B) {
-  return (A&-8388481)|(B&8388480);
-}
-
-We currently generate:
-	bfc	r0, #7, #16
-	movw	r2, #:lower16:8388480
-	movt	r2, #:upper16:8388480
-	and	r1, r1, r2
-	orr	r0, r1, r0
-	bx	lr
-
-The following is much shorter:
-	lsr	r1, r1, #7
-	bfi	r0, r1, #7, #16
-	bx	lr
-
-
-//===---------------------------------------------------------------------===//
-
 The code generated for bswap on armv4/5 (CPUs without rev) is less than ideal:
 
 int a(int x) { return __builtin_bswap32(x); }