forked from OSchip/llvm-project
77 lines
2.4 KiB
LLVM
77 lines
2.4 KiB
LLVM
; RUN: opt -basicaa -loop-load-elim -S < %s | FileCheck %s
|
|
|
|
; When optimizing for size don't eliminate in this loop because the loop would
|
|
; have to be versioned first because A and C may alias.
|
|
;
|
|
; for (unsigned i = 0; i < 100; i++) {
|
|
; A[i+1] = B[i] + 2;
|
|
; C[i] = A[i] * 2;
|
|
; }
|
|
|
|
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
|
|
|
|
; CHECK-LABEL: @f(
|
|
define void @f(i32* %A, i32* %B, i32* %C, i64 %N) optsize {
|
|
|
|
entry:
|
|
br label %for.body
|
|
|
|
for.body: ; preds = %for.body, %entry
|
|
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
|
|
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
|
|
|
|
%Aidx_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next
|
|
%Bidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
|
|
%Cidx = getelementptr inbounds i32, i32* %C, i64 %indvars.iv
|
|
%Aidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
|
|
|
|
%b = load i32, i32* %Bidx, align 4
|
|
%a_p1 = add i32 %b, 2
|
|
store i32 %a_p1, i32* %Aidx_next, align 4
|
|
|
|
%a = load i32, i32* %Aidx, align 4
|
|
; CHECK: %c = mul i32 %a, 2
|
|
%c = mul i32 %a, 2
|
|
store i32 %c, i32* %Cidx, align 4
|
|
|
|
%exitcond = icmp eq i64 %indvars.iv.next, %N
|
|
br i1 %exitcond, label %for.end, label %for.body
|
|
|
|
for.end: ; preds = %for.body
|
|
ret void
|
|
}
|
|
|
|
; Same loop but with noalias on %A and %C. In this case load-eliminate even
|
|
; with -Os.
|
|
|
|
; CHECK-LABEL: @g(
|
|
define void @g(i32* noalias %A, i32* %B, i32* noalias %C, i64 %N) optsize {
|
|
|
|
entry:
|
|
br label %for.body
|
|
|
|
for.body: ; preds = %for.body, %entry
|
|
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
|
|
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
|
|
|
|
%Aidx_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next
|
|
%Bidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
|
|
%Cidx = getelementptr inbounds i32, i32* %C, i64 %indvars.iv
|
|
%Aidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
|
|
|
|
%b = load i32, i32* %Bidx, align 4
|
|
%a_p1 = add i32 %b, 2
|
|
store i32 %a_p1, i32* %Aidx_next, align 4
|
|
|
|
%a = load i32, i32* %Aidx, align 4
|
|
; CHECK: %c = mul i32 %store_forwarded, 2
|
|
%c = mul i32 %a, 2
|
|
store i32 %c, i32* %Cidx, align 4
|
|
|
|
%exitcond = icmp eq i64 %indvars.iv.next, %N
|
|
br i1 %exitcond, label %for.end, label %for.body
|
|
|
|
for.end: ; preds = %for.body
|
|
ret void
|
|
}
|