llvm/test/CodeGen/X86/constant-hoisting-and.ll
Craig Topper 50bf4331f4 [X86] Teach constant hoisting that ANDs with 64-bit immediates in the range 0x80000000-0xffffffff can be handled cheaply and don't need to be hoisted.
Most importantly, this keeps constant hoisting from preventing instruction selections ability to turn an AND with 0xffffffff into a move into a 32-bit subregister.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249370 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-06 02:50:24 +00:00

20 lines
519 B
LLVM

; RUN: llc < %s -O3 -march=x86-64 |FileCheck %s
define i64 @foo(i1 %z, i64 %data1, i64 %data2)
{
; If constant 4294967294 is hoisted to a variable, then we won't be able to use
; the implicit zero extension of 32-bit operations to handle the AND.
entry:
%val1 = and i64 %data1, 4294967294
br i1 %z, label %End, label %L_val2
; CHECK: andl $-2, {{.*}}
; CHECK: andl $-2, {{.*}}
L_val2:
%val2 = and i64 %data2, 4294967294
br label %End
End:
%p1 = phi i64 [%val1,%entry], [%val2,%L_val2]
ret i64 %p1
}