maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/test/Transforms/IndVarSimplify/exit_value_test2.ll

75 lines
2.7 KiB
LLVM
Raw Normal View History

Enable exitValue rewrite only when the cost of expansion is low. The patch evaluates the expansion cost of exitValue in indVarSimplify pass, and only does the rewriting when the expansion cost is low or loop can be deleted with the rewriting. It provides an option "-replexitval=" to control the default aggressiveness of the exitvalue rewriting. It also fixes some missing cases in SCEVExpander::isHighCostExpansionHelper to enhance the evaluation of SCEV expansion cost. Differential Revision: http://reviews.llvm.org/D9800 llvm-svn: 238507
2015-05-29 05:49:07 +08:00
; PR23538
; RUN: opt < %s -indvars -loop-deletion -S | FileCheck %s
; Check IndVarSimplify should not replace exit value because or else
; udiv will be introduced by expand and the cost will be high.
declare void @_Z3mixRjj(i32* dereferenceable(4), i32)
Add address space mangling to lifetime intrinsics In preparation for allowing allocas to have non-0 addrspace. llvm-svn: 299876
2017-04-11 04:18:21 +08:00
declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture)
declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture)
Enable exitValue rewrite only when the cost of expansion is low. The patch evaluates the expansion cost of exitValue in indVarSimplify pass, and only does the rewriting when the expansion cost is low or loop can be deleted with the rewriting. It provides an option "-replexitval=" to control the default aggressiveness of the exitvalue rewriting. It also fixes some missing cases in SCEVExpander::isHighCostExpansionHelper to enhance the evaluation of SCEV expansion cost. Differential Revision: http://reviews.llvm.org/D9800 llvm-svn: 238507
2015-05-29 05:49:07 +08:00
define i32 @_Z3fooPKcjj(i8* nocapture readonly %s, i32 %len, i32 %c) {
[SCEV/IndVars] Always compute loop exiting values if the backedge count is 0 If SCEV can prove that the backedge taken count for a loop is zero, it does not need to "understand" a recursive PHI to compute its exiting value. This should fix PR33885. llvm-svn: 309758
2017-08-02 06:37:58 +08:00
; CHECK-LABEL: @_Z3fooPKcjj(
; CHECK-NOT: udiv
Enable exitValue rewrite only when the cost of expansion is low. The patch evaluates the expansion cost of exitValue in indVarSimplify pass, and only does the rewriting when the expansion cost is low or loop can be deleted with the rewriting. It provides an option "-replexitval=" to control the default aggressiveness of the exitvalue rewriting. It also fixes some missing cases in SCEVExpander::isHighCostExpansionHelper to enhance the evaluation of SCEV expansion cost. Differential Revision: http://reviews.llvm.org/D9800 llvm-svn: 238507
2015-05-29 05:49:07 +08:00
entry:
%a = alloca i32, align 4
%tmp = bitcast i32* %a to i8*
Add address space mangling to lifetime intrinsics In preparation for allowing allocas to have non-0 addrspace. llvm-svn: 299876
2017-04-11 04:18:21 +08:00
call void @llvm.lifetime.start.p0i8(i64 4, i8* %tmp)
Enable exitValue rewrite only when the cost of expansion is low. The patch evaluates the expansion cost of exitValue in indVarSimplify pass, and only does the rewriting when the expansion cost is low or loop can be deleted with the rewriting. It provides an option "-replexitval=" to control the default aggressiveness of the exitvalue rewriting. It also fixes some missing cases in SCEVExpander::isHighCostExpansionHelper to enhance the evaluation of SCEV expansion cost. Differential Revision: http://reviews.llvm.org/D9800 llvm-svn: 238507
2015-05-29 05:49:07 +08:00
store i32 -1640531527, i32* %a, align 4
%cmp8 = icmp ugt i32 %len, 11
br i1 %cmp8, label %while.body.lr.ph, label %while.end
while.body.lr.ph: ; preds = %entry
br label %while.body
while.body: ; preds = %while.body, %while.body.lr.ph
%keylen.010 = phi i32 [ %len, %while.body.lr.ph ], [ %sub, %while.body ]
%s.addr.09 = phi i8* [ %s, %while.body.lr.ph ], [ %add.ptr, %while.body ]
%tmp1 = bitcast i8* %s.addr.09 to i32*
%tmp2 = load i32, i32* %tmp1, align 4
%shl.i = shl i32 %tmp2, 1
%and.i = and i32 %shl.i, 16843008
%tmp3 = load i32, i32* %a, align 4
%sub.i = add i32 %tmp3, %tmp2
%add = sub i32 %sub.i, %and.i
store i32 %add, i32* %a, align 4
%add.ptr = getelementptr inbounds i8, i8* %s.addr.09, i64 12
%sub = add i32 %keylen.010, -12
%cmp = icmp ugt i32 %sub, 11
br i1 %cmp, label %while.body, label %while.cond.while.end_crit_edge
while.cond.while.end_crit_edge: ; preds = %while.body
%sub.lcssa = phi i32 [ %sub, %while.body ]
br label %while.end
while.end: ; preds = %while.cond.while.end_crit_edge, %entry
%keylen.0.lcssa = phi i32 [ %sub.lcssa, %while.cond.while.end_crit_edge ], [ %len, %entry ]
call void @_Z3mixRjj(i32* dereferenceable(4) %a, i32 %keylen.0.lcssa)
%tmp4 = load i32, i32* %a, align 4
Add address space mangling to lifetime intrinsics In preparation for allowing allocas to have non-0 addrspace. llvm-svn: 299876
2017-04-11 04:18:21 +08:00
call void @llvm.lifetime.end.p0i8(i64 4, i8* %tmp)
Enable exitValue rewrite only when the cost of expansion is low. The patch evaluates the expansion cost of exitValue in indVarSimplify pass, and only does the rewriting when the expansion cost is low or loop can be deleted with the rewriting. It provides an option "-replexitval=" to control the default aggressiveness of the exitvalue rewriting. It also fixes some missing cases in SCEVExpander::isHighCostExpansionHelper to enhance the evaluation of SCEV expansion cost. Differential Revision: http://reviews.llvm.org/D9800 llvm-svn: 238507
2015-05-29 05:49:07 +08:00
ret i32 %tmp4
}
[SCEV/IndVars] Always compute loop exiting values if the backedge count is 0 If SCEV can prove that the backedge taken count for a loop is zero, it does not need to "understand" a recursive PHI to compute its exiting value. This should fix PR33885. llvm-svn: 309758
2017-08-02 06:37:58 +08:00
define i32 @zero_backedge_count_test(i32 %unknown_init, i32* %unknown_mem) {
; CHECK-LABEL: @zero_backedge_count_test(
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry], [ %iv.inc, %loop ]
%unknown_phi = phi i32 [ %unknown_init, %entry ], [ %unknown_next, %loop ]
%iv.inc = add i32 %iv, 1
%be_taken = icmp ne i32 %iv.inc, 1
%unknown_next = load volatile i32, i32* %unknown_mem
br i1 %be_taken, label %loop, label %leave
leave:
; We can fold %unknown_phi even though the backedge value for it is completely
; unknown, since we can prove that the loop's backedge taken count is 0.
; CHECK: leave:
; CHECK: ret i32 %unknown_init
%exit_val = phi i32 [ %unknown_phi, %loop ]
ret i32 %exit_val
}