llvm-6502/test/Transforms/LICM/sink_load.ll

22 lines
678 B
LLVM
Raw Normal View History

; To reduce register pressure, if a load is hoistable out of the loop, and the
; result of the load is only used outside of the loop, sink the load instead of
; hoisting it!
;
; RUN: llvm-as < %s | opt -licm | llvm-dis | %prcontext load 1 | grep Out:
@X = global i32 5 ; <i32*> [#uses=1]
define i32 @test(i32 %N) {
Entry:
br label %Loop
Loop: ; preds = %Loop, %Entry
%N_addr.0.pn = phi i32 [ %dec, %Loop ], [ %N, %Entry ] ; <i32> [#uses=2]
%tmp.6 = load i32* @X ; <i32> [#uses=1]
%dec = add i32 %N_addr.0.pn, -1 ; <i32> [#uses=1]
%tmp.1 = icmp ne i32 %N_addr.0.pn, 1 ; <i1> [#uses=1]
br i1 %tmp.1, label %Loop, label %Out
Out: ; preds = %Loop
ret i32 %tmp.6
}