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clang-p2996/llvm/test/Transforms/IndVarSimplify/loop-predication.ll
Nikita Popov c8b675eaa1 [SCEV] Use umin_seq for BECount of multi-exit loops 
When computing the BECount for multi-exit loops, we need to combine
individual exit counts using umin_seq rather than umin. This is
because an earlier exit may exit on the first iteration, in which
case later exit expressions will not be evaluated and could be
poisonous. We cannot propagate potential poison values from later
exits.

In particular, this avoids the introduction of "branch on poison"
UB when optimizing multi-exit loops.

Differential Revision: https://reviews.llvm.org/D124910
2022-05-21 15:48:14 +02:00

844 lines
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -indvars -indvars-predicate-loops=1 -S | FileCheck %s
declare void @prevent_merging()
; Base case
define i32 @test1(i32* %array, i32 %length, i32 %n) {
; CHECK-LABEL: @test1(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: [[UMAX:%.*]] = call i32 @llvm.umax.i32(i32 [[N:%.*]], i32 1)
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[UMAX]], -1
; CHECK-NEXT: [[TMP1:%.*]] = freeze i32 [[TMP0]]
; CHECK-NEXT: [[UMIN:%.*]] = call i32 @llvm.umin.i32(i32 [[TMP1]], i32 [[LENGTH:%.*]])
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[LENGTH]], [[UMIN]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: br i1 [[TMP2]], label [[GUARDED]], label [[DEOPT:%.*]], !prof [[PROF0:![0-9]+]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC]], [[ARRAY_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i32 [[I_NEXT]], [[N]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
loop.preheader: ; preds = %entry
br label %loop
loop: ; preds = %guarded, %loop.preheader
%loop.acc = phi i32 [ %loop.acc.next, %guarded ], [ 0, %loop.preheader ]
%i = phi i32 [ %i.next, %guarded ], [ 0, %loop.preheader ]
%within.bounds = icmp ult i32 %i, %length
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
%i.i64 = zext i32 %i to i64
%array.i.ptr = getelementptr inbounds i32, i32* %array, i64 %i.i64
%array.i = load i32, i32* %array.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc, %array.i
%i.next = add nuw i32 %i, 1
%continue = icmp ult i32 %i.next, %n
br i1 %continue, label %loop, label %exit
exit: ; preds = %guarded, %entry
%result = phi i32 [ %loop.acc.next, %guarded ]
ret i32 %result
}
; Has side effect which must be reflected
define i32 @neg_store(i32* %array, i32 %length, i32 %n) {
; CHECK-LABEL: @neg_store(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[I]], [[LENGTH:%.*]]
; CHECK-NEXT: br i1 [[WITHIN_BOUNDS]], label [[GUARDED]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC]], [[ARRAY_I]]
; CHECK-NEXT: store i32 0, i32* [[ARRAY_I_PTR]], align 4
; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i32 [[I_NEXT]], [[N:%.*]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
loop.preheader: ; preds = %entry
br label %loop
loop: ; preds = %guarded, %loop.preheader
%loop.acc = phi i32 [ %loop.acc.next, %guarded ], [ 0, %loop.preheader ]
%i = phi i32 [ %i.next, %guarded ], [ 0, %loop.preheader ]
%within.bounds = icmp ult i32 %i, %length
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
%i.i64 = zext i32 %i to i64
%array.i.ptr = getelementptr inbounds i32, i32* %array, i64 %i.i64
%array.i = load i32, i32* %array.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc, %array.i
store i32 0, i32* %array.i.ptr
%i.next = add nuw i32 %i, 1
%continue = icmp ult i32 %i.next, %n
br i1 %continue, label %loop, label %exit
exit: ; preds = %guarded, %entry
%result = phi i32 [ %loop.acc.next, %guarded ]
ret i32 %result
}
declare void @maythrow()
; May exit through implicit exception edge
define i32 @neg_implicit_exit(i32* %array, i32 %length, i32 %n) {
; CHECK-LABEL: @neg_implicit_exit(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: call void @maythrow()
; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[I]], [[LENGTH:%.*]]
; CHECK-NEXT: br i1 [[WITHIN_BOUNDS]], label [[GUARDED]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC]], [[ARRAY_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i32 [[I_NEXT]], [[N:%.*]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
loop.preheader: ; preds = %entry
br label %loop
loop: ; preds = %guarded, %loop.preheader
%loop.acc = phi i32 [ %loop.acc.next, %guarded ], [ 0, %loop.preheader ]
%i = phi i32 [ %i.next, %guarded ], [ 0, %loop.preheader ]
call void @maythrow()
%within.bounds = icmp ult i32 %i, %length
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
%i.i64 = zext i32 %i to i64
%array.i.ptr = getelementptr inbounds i32, i32* %array, i64 %i.i64
%array.i = load i32, i32* %array.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc, %array.i
%i.next = add nuw i32 %i, 1
%continue = icmp ult i32 %i.next, %n
br i1 %continue, label %loop, label %exit
exit: ; preds = %guarded, %entry
%result = phi i32 [ %loop.acc.next, %guarded ]
ret i32 %result
}
; Base case, but in LFTR form (just for basic correctness checking)
define i32 @test2(i32* %array, i32 %length, i32 %n) {
; CHECK-LABEL: @test2(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[N:%.*]], -1
; CHECK-NEXT: [[TMP1:%.*]] = freeze i32 [[TMP0]]
; CHECK-NEXT: [[UMIN:%.*]] = call i32 @llvm.umin.i32(i32 [[TMP1]], i32 [[LENGTH:%.*]])
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[LENGTH]], [[UMIN]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: br i1 [[TMP2]], label [[GUARDED]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC]], [[ARRAY_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ne i32 [[I_NEXT]], [[N]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
loop.preheader: ; preds = %entry
br label %loop
loop: ; preds = %guarded, %loop.preheader
%loop.acc = phi i32 [ %loop.acc.next, %guarded ], [ 0, %loop.preheader ]
%i = phi i32 [ %i.next, %guarded ], [ 0, %loop.preheader ]
%within.bounds = icmp ne i32 %i, %length
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
%i.i64 = zext i32 %i to i64
%array.i.ptr = getelementptr inbounds i32, i32* %array, i64 %i.i64
%array.i = load i32, i32* %array.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc, %array.i
%i.next = add nuw i32 %i, 1
%continue = icmp ne i32 %i.next, %n
br i1 %continue, label %loop, label %exit
exit: ; preds = %guarded, %entry
%result = phi i32 [ %loop.acc.next, %guarded ]
ret i32 %result
}
; br (and rcheck1, rcheck2)
define i32 @two_range_checks(i32* %array.1, i32 %length.1, i32* %array.2, i32 %length.2, i32 %n) {
; CHECK-LABEL: @two_range_checks(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: [[UMIN:%.*]] = call i32 @llvm.umin.i32(i32 [[LENGTH_2:%.*]], i32 [[LENGTH_1:%.*]])
; CHECK-NEXT: [[UMAX:%.*]] = call i32 @llvm.umax.i32(i32 [[N:%.*]], i32 1)
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[UMAX]], -1
; CHECK-NEXT: [[TMP1:%.*]] = freeze i32 [[TMP0]]
; CHECK-NEXT: [[UMIN1:%.*]] = call i32 @llvm.umin.i32(i32 [[TMP1]], i32 [[UMIN]])
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[UMIN]], [[UMIN1]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: br i1 [[TMP2]], label [[GUARDED]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_1_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_1:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_1_I:%.*]] = load i32, i32* [[ARRAY_1_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_1:%.*]] = add i32 [[LOOP_ACC]], [[ARRAY_1_I]]
; CHECK-NEXT: [[ARRAY_2_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_2:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_2_I:%.*]] = load i32, i32* [[ARRAY_2_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC_1]], [[ARRAY_2_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i32 [[I_NEXT]], [[N]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
loop.preheader: ; preds = %entry
br label %loop
loop: ; preds = %guarded, %loop.preheader
%loop.acc = phi i32 [ %loop.acc.next, %guarded ], [ 0, %loop.preheader ]
%i = phi i32 [ %i.next, %guarded ], [ 0, %loop.preheader ]
%within.bounds.1 = icmp ult i32 %i, %length.1
%within.bounds.2 = icmp ult i32 %i, %length.2
%within.bounds = and i1 %within.bounds.1, %within.bounds.2
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
%i.i64 = zext i32 %i to i64
%array.1.i.ptr = getelementptr inbounds i32, i32* %array.1, i64 %i.i64
%array.1.i = load i32, i32* %array.1.i.ptr, align 4
%loop.acc.1 = add i32 %loop.acc, %array.1.i
%array.2.i.ptr = getelementptr inbounds i32, i32* %array.2, i64 %i.i64
%array.2.i = load i32, i32* %array.2.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc.1, %array.2.i
%i.next = add nuw i32 %i, 1
%continue = icmp ult i32 %i.next, %n
br i1 %continue, label %loop, label %exit
exit: ; preds = %guarded, %entry
%result = phi i32 [ %loop.acc.next, %guarded ]
ret i32 %result
}
define i32 @three_range_checks(i32* %array.1, i32 %length.1, i32* %array.2, i32 %length.2, i32* %array.3, i32 %length.3, i32 %n) {
; CHECK-LABEL: @three_range_checks(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: [[UMIN:%.*]] = call i32 @llvm.umin.i32(i32 [[LENGTH_3:%.*]], i32 [[LENGTH_2:%.*]])
; CHECK-NEXT: [[UMIN1:%.*]] = call i32 @llvm.umin.i32(i32 [[UMIN]], i32 [[LENGTH_1:%.*]])
; CHECK-NEXT: [[UMAX:%.*]] = call i32 @llvm.umax.i32(i32 [[N:%.*]], i32 1)
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[UMAX]], -1
; CHECK-NEXT: [[TMP1:%.*]] = freeze i32 [[TMP0]]
; CHECK-NEXT: [[UMIN2:%.*]] = call i32 @llvm.umin.i32(i32 [[TMP1]], i32 [[UMIN1]])
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[UMIN1]], [[UMIN2]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: br i1 [[TMP2]], label [[GUARDED]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_1_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_1:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_1_I:%.*]] = load i32, i32* [[ARRAY_1_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_1:%.*]] = add i32 [[LOOP_ACC]], [[ARRAY_1_I]]
; CHECK-NEXT: [[ARRAY_2_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_2:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_2_I:%.*]] = load i32, i32* [[ARRAY_2_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_2:%.*]] = add i32 [[LOOP_ACC_1]], [[ARRAY_2_I]]
; CHECK-NEXT: [[ARRAY_3_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_3:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_3_I:%.*]] = load i32, i32* [[ARRAY_3_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC_2]], [[ARRAY_3_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i32 [[I_NEXT]], [[N]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
loop.preheader: ; preds = %entry
br label %loop
loop: ; preds = %guarded, %loop.preheader
%loop.acc = phi i32 [ %loop.acc.next, %guarded ], [ 0, %loop.preheader ]
%i = phi i32 [ %i.next, %guarded ], [ 0, %loop.preheader ]
%within.bounds.1 = icmp ult i32 %i, %length.1
%within.bounds.2 = icmp ult i32 %i, %length.2
%within.bounds.3 = icmp ult i32 %i, %length.3
%within.bounds.1.and.2 = and i1 %within.bounds.1, %within.bounds.2
%within.bounds = and i1 %within.bounds.1.and.2, %within.bounds.3
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
%i.i64 = zext i32 %i to i64
%array.1.i.ptr = getelementptr inbounds i32, i32* %array.1, i64 %i.i64
%array.1.i = load i32, i32* %array.1.i.ptr, align 4
%loop.acc.1 = add i32 %loop.acc, %array.1.i
%array.2.i.ptr = getelementptr inbounds i32, i32* %array.2, i64 %i.i64
%array.2.i = load i32, i32* %array.2.i.ptr, align 4
%loop.acc.2 = add i32 %loop.acc.1, %array.2.i
%array.3.i.ptr = getelementptr inbounds i32, i32* %array.3, i64 %i.i64
%array.3.i = load i32, i32* %array.3.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc.2, %array.3.i
%i.next = add nuw i32 %i, 1
%continue = icmp ult i32 %i.next, %n
br i1 %continue, label %loop, label %exit
exit: ; preds = %guarded, %entry
%result = phi i32 [ %loop.acc.next, %guarded ]
ret i32 %result
}
; Analogous to the above, but with two distinct branches (on different conditions)
define i32 @distinct_checks(i32* %array.1, i32 %length.1, i32* %array.2, i32 %length.2, i32* %array.3, i32 %length.3, i32 %n) {
; CHECK-LABEL: @distinct_checks(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: [[UMAX:%.*]] = call i32 @llvm.umax.i32(i32 [[N:%.*]], i32 1)
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[UMAX]], -1
; CHECK-NEXT: [[TMP1:%.*]] = freeze i32 [[TMP0]]
; CHECK-NEXT: [[TMP2:%.*]] = freeze i32 [[LENGTH_2:%.*]]
; CHECK-NEXT: [[UMIN:%.*]] = call i32 @llvm.umin.i32(i32 [[TMP1]], i32 [[TMP2]])
; CHECK-NEXT: [[UMIN1:%.*]] = call i32 @llvm.umin.i32(i32 [[UMIN]], i32 [[LENGTH_1:%.*]])
; CHECK-NEXT: [[TMP3:%.*]] = icmp ne i32 [[LENGTH_1]], [[UMIN1]]
; CHECK-NEXT: [[TMP4:%.*]] = icmp ne i32 [[LENGTH_2]], [[UMIN1]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED1:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED1]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: br i1 [[TMP3]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_1_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_1:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_1_I:%.*]] = load i32, i32* [[ARRAY_1_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_1:%.*]] = add i32 [[LOOP_ACC]], [[ARRAY_1_I]]
; CHECK-NEXT: br i1 [[TMP4]], label [[GUARDED1]], label [[DEOPT2:%.*]], !prof [[PROF0]]
; CHECK: deopt2:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded1:
; CHECK-NEXT: [[ARRAY_3_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_3:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_3_I:%.*]] = load i32, i32* [[ARRAY_3_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC_1]], [[ARRAY_3_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i32 [[I_NEXT]], [[N]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED1]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
loop.preheader: ; preds = %entry
br label %loop
loop: ; preds = %guarded4, %loop.preheader
%loop.acc = phi i32 [ %loop.acc.next, %guarded1 ], [ 0, %loop.preheader ]
%i = phi i32 [ %i.next, %guarded1 ], [ 0, %loop.preheader ]
%within.bounds.1 = icmp ult i32 %i, %length.1
br i1 %within.bounds.1, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
%i.i64 = zext i32 %i to i64
%array.1.i.ptr = getelementptr inbounds i32, i32* %array.1, i64 %i.i64
%array.1.i = load i32, i32* %array.1.i.ptr, align 4
%loop.acc.1 = add i32 %loop.acc, %array.1.i
%within.bounds.2 = icmp ult i32 %i, %length.2
br i1 %within.bounds.2, label %guarded1, label %deopt2, !prof !0
deopt2: ; preds = %guarded
call void @prevent_merging()
ret i32 -1
guarded1: ; preds = %guarded1
%array.3.i.ptr = getelementptr inbounds i32, i32* %array.3, i64 %i.i64
%array.3.i = load i32, i32* %array.3.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc.1, %array.3.i
%i.next = add nuw i32 %i, 1
%continue = icmp ult i32 %i.next, %n
br i1 %continue, label %loop, label %exit
exit:
%result = phi i32 [ %loop.acc.next, %guarded1 ]
ret i32 %result
}
define i32 @duplicate_checks(i32* %array.1, i32* %array.2, i32* %array.3, i32 %length, i32 %n) {
; CHECK-LABEL: @duplicate_checks(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: [[UMAX:%.*]] = call i32 @llvm.umax.i32(i32 [[N:%.*]], i32 1)
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[UMAX]], -1
; CHECK-NEXT: [[TMP1:%.*]] = freeze i32 [[TMP0]]
; CHECK-NEXT: [[UMIN:%.*]] = call i32 @llvm.umin.i32(i32 [[TMP1]], i32 [[LENGTH:%.*]])
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[LENGTH]], [[UMIN]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED1:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED1]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: br i1 [[TMP2]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_1_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_1:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_1_I:%.*]] = load i32, i32* [[ARRAY_1_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_1:%.*]] = add i32 [[LOOP_ACC]], [[ARRAY_1_I]]
; CHECK-NEXT: br i1 true, label [[GUARDED1]], label [[DEOPT2:%.*]], !prof [[PROF0]]
; CHECK: deopt2:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded1:
; CHECK-NEXT: [[ARRAY_3_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY_3:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_3_I:%.*]] = load i32, i32* [[ARRAY_3_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC_1]], [[ARRAY_3_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i32 [[I_NEXT]], [[N]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED1]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
loop.preheader: ; preds = %entry
br label %loop
loop: ; preds = %guarded4, %loop.preheader
%loop.acc = phi i32 [ %loop.acc.next, %guarded1 ], [ 0, %loop.preheader ]
%i = phi i32 [ %i.next, %guarded1 ], [ 0, %loop.preheader ]
%within.bounds.1 = icmp ult i32 %i, %length
br i1 %within.bounds.1, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
%i.i64 = zext i32 %i to i64
%array.1.i.ptr = getelementptr inbounds i32, i32* %array.1, i64 %i.i64
%array.1.i = load i32, i32* %array.1.i.ptr, align 4
%loop.acc.1 = add i32 %loop.acc, %array.1.i
%within.bounds.2 = icmp ult i32 %i, %length
br i1 %within.bounds.2, label %guarded1, label %deopt2, !prof !0
deopt2: ; preds = %guarded
call void @prevent_merging()
ret i32 -1
guarded1: ; preds = %guarded1
%array.3.i.ptr = getelementptr inbounds i32, i32* %array.3, i64 %i.i64
%array.3.i = load i32, i32* %array.3.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc.1, %array.3.i
%i.next = add nuw i32 %i, 1
%continue = icmp ult i32 %i.next, %n
br i1 %continue, label %loop, label %exit
exit:
%result = phi i32 [ %loop.acc.next, %guarded1 ]
ret i32 %result
}
define i32 @provably_taken(i32* %array, i32* %length.ptr) {
; CHECK-LABEL: @provably_taken(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: br i1 false, label [[GUARDED]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC]], [[ARRAY_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT: br i1 true, label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
loop.preheader:
%length = load i32, i32* %length.ptr, !range !2
br label %loop
loop: ; preds = %guarded, %loop.preheader
%loop.acc = phi i32 [ %loop.acc.next, %guarded ], [ 0, %loop.preheader ]
%i = phi i32 [ %i.next, %guarded ], [ 0, %loop.preheader ]
%within.bounds = icmp ult i32 %i, %length
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
%i.i64 = zext i32 %i to i64
%array.i.ptr = getelementptr inbounds i32, i32* %array, i64 %i.i64
%array.i = load i32, i32* %array.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc, %array.i
%i.next = add nuw i32 %i, 1
%continue = icmp slt i32 %i.next, 200
br i1 %continue, label %loop, label %exit
exit: ; preds = %guarded
%result = phi i32 [ %loop.acc.next, %guarded ]
ret i32 %result
}
; Non-latch exits can still be predicated
define i32 @unconditional_latch(i32* %a, i32 %length) {
; CHECK-LABEL: @unconditional_latch(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: br i1 false, label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: br label [[LOOP]]
;
loop.preheader:
br label %loop
loop: ; preds = %guarded, %loop.preheader
%i = phi i32 [ %i.next, %guarded ], [ 400, %loop.preheader ]
%within.bounds = icmp ult i32 %i, %length
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
%i.next = add i32 %i, 1
br label %loop
}
; Side effect in loop must run proper number of times
define i32 @unconditional_latch_with_side_effect(i32* %a, i32 %length) {
; CHECK-LABEL: @unconditional_latch_with_side_effect(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED:%.*]] ], [ 400, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[I]], [[LENGTH:%.*]]
; CHECK-NEXT: br i1 [[WITHIN_BOUNDS]], label [[GUARDED]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: store volatile i32 0, i32* [[A:%.*]], align 4
; CHECK-NEXT: [[I_NEXT]] = add i32 [[I]], 1
; CHECK-NEXT: br label [[LOOP]]
;
loop.preheader:
br label %loop
loop: ; preds = %guarded, %loop.preheader
%i = phi i32 [ %i.next, %guarded ], [ 400, %loop.preheader ]
%within.bounds = icmp ult i32 %i, %length
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded: ; preds = %loop
store volatile i32 0, i32* %a
%i.next = add i32 %i, 1
br label %loop
}
; Demonstrate that this approach works with IVs of different steps, and types
; This version uses a manually lftred exit condition to work around an issue described
; in detail on next test.
define i32 @different_ivs(i32* %array, i32 %length, i32 %n) {
; CHECK-LABEL: @different_ivs(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: [[N64:%.*]] = zext i32 [[N:%.*]] to i64
; CHECK-NEXT: [[UMAX:%.*]] = call i64 @llvm.umax.i64(i64 [[N64]], i64 1)
; CHECK-NEXT: [[TMP0:%.*]] = add nsw i64 [[UMAX]], -1
; CHECK-NEXT: [[TMP1:%.*]] = freeze i64 [[TMP0]]
; CHECK-NEXT: [[TMP2:%.*]] = zext i32 [[LENGTH:%.*]] to i64
; CHECK-NEXT: [[UMIN:%.*]] = call i64 @llvm.umin.i64(i64 [[TMP1]], i64 [[TMP2]])
; CHECK-NEXT: [[TMP3:%.*]] = zext i32 [[LENGTH]] to i64
; CHECK-NEXT: [[TMP4:%.*]] = icmp ne i64 [[TMP3]], [[UMIN]]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i64 [ [[I_NEXT:%.*]], [[GUARDED]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: br i1 [[TMP4]], label [[GUARDED]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC]], [[ARRAY_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw nsw i64 [[I]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i64 [[I_NEXT]], [[N64]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
loop.preheader:
%j.start = sub nuw nsw i32 %length, 1
%n64 = zext i32 %n to i64
br label %loop
loop:
%loop.acc = phi i32 [ %loop.acc.next, %guarded ], [ 0, %loop.preheader ]
%i = phi i64 [ %i.next, %guarded ], [ 0, %loop.preheader ]
%j = phi i32 [ %j.next, %guarded ], [ %j.start, %loop.preheader ]
%within.bounds = icmp ne i32 %j, -1
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt:
call void @prevent_merging()
ret i32 -1
guarded:
%array.i.ptr = getelementptr inbounds i32, i32* %array, i64 %i
%array.i = load i32, i32* %array.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc, %array.i
%i.next = add nuw i64 %i, 1
%j.next = sub nuw i32 %j, 1
%continue = icmp ult i64 %i.next, %n64
br i1 %continue, label %loop, label %exit
exit:
%result = phi i32 [ %loop.acc.next, %guarded ]
ret i32 %result
}
; TODO: We're failing to compute an exit count for the bounds check.
; From some quick analysis, it looks like we don't handle -1 step
; in howManyLessThans. Should be a simple fix.
define i32 @different_ivs2(i32* %array, i32 %length, i32 %n) {
; CHECK-LABEL: @different_ivs2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[POS_LENGTH:%.*]] = icmp sgt i32 [[LENGTH:%.*]], 0
; CHECK-NEXT: br i1 [[POS_LENGTH]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
; CHECK: loop.preheader:
; CHECK-NEXT: [[J_START:%.*]] = sub nuw nsw i32 [[LENGTH]], 1
; CHECK-NEXT: [[N64:%.*]] = zext i32 [[N:%.*]] to i64
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED:%.*]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[I:%.*]] = phi i64 [ [[I_NEXT:%.*]], [[GUARDED]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[J:%.*]] = phi i32 [ [[J_NEXT:%.*]], [[GUARDED]] ], [ [[J_START]], [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[J]], [[LENGTH]]
; CHECK-NEXT: br i1 [[WITHIN_BOUNDS]], label [[GUARDED]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded:
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC]], [[ARRAY_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw nsw i64 [[I]], 1
; CHECK-NEXT: [[J_NEXT]] = sub nuw i32 [[J]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i64 [[I_NEXT]], [[N64]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT_LOOPEXIT:%.*]]
; CHECK: exit.loopexit:
; CHECK-NEXT: [[LOOP_ACC_NEXT_LCSSA:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED]] ]
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[LOOP_ACC_NEXT_LCSSA]], [[EXIT_LOOPEXIT]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
entry:
%pos_length = icmp sgt i32 %length, 0
br i1 %pos_length, label %loop.preheader, label %exit
loop.preheader:
%j.start = sub nuw nsw i32 %length, 1
%n64 = zext i32 %n to i64
br label %loop
loop:
%loop.acc = phi i32 [ %loop.acc.next, %guarded ], [ 0, %loop.preheader ]
%i = phi i64 [ %i.next, %guarded ], [ 0, %loop.preheader ]
%j = phi i32 [ %j.next, %guarded ], [ %j.start, %loop.preheader ]
%within.bounds = icmp ult i32 %j, %length
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt:
call void @prevent_merging()
ret i32 -1
guarded:
%array.i.ptr = getelementptr inbounds i32, i32* %array, i64 %i
%array.i = load i32, i32* %array.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc, %array.i
%i.next = add nuw i64 %i, 1
%j.next = sub nuw i32 %j, 1
%continue = icmp ult i64 %i.next, %n64
br i1 %continue, label %loop, label %exit
exit:
%result = phi i32 [ %loop.acc.next, %guarded ], [0, %entry]
ret i32 %result
}
; If we have a dominating exit (exit1) which can't be itself rewritten, we
; can't rewrite a later exit (exit2). Doing so would cause the loop to exit
; from the exit2 when it should have exited from exit1.
define i32 @neg_dominating_exit(i32* %array, i32 %length, i32 %length2, i32 %n) {
; CHECK-LABEL: @neg_dominating_exit(
; CHECK-NEXT: loop.preheader:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[LOOP_ACC:%.*]] = phi i32 [ [[LOOP_ACC_NEXT:%.*]], [[GUARDED2:%.*]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[GUARDED2]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[I]], [[LENGTH:%.*]]
; CHECK-NEXT: br i1 [[WITHIN_BOUNDS]], label [[GUARDED:%.*]], label [[DEOPT:%.*]], !prof [[PROF0]]
; CHECK: deopt:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ [[LOOP_ACC]], [[LOOP]] ]
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 [[RESULT]]
; CHECK: guarded:
; CHECK-NEXT: [[WITHIN_BOUNDS2:%.*]] = icmp ult i32 [[I]], [[LENGTH2:%.*]]
; CHECK-NEXT: br i1 [[WITHIN_BOUNDS2]], label [[GUARDED2]], label [[DEOPT2:%.*]], !prof [[PROF0]]
; CHECK: deopt2:
; CHECK-NEXT: call void @prevent_merging()
; CHECK-NEXT: ret i32 -1
; CHECK: guarded2:
; CHECK-NEXT: [[I_I64:%.*]] = zext i32 [[I]] to i64
; CHECK-NEXT: [[ARRAY_I_PTR:%.*]] = getelementptr inbounds i32, i32* [[ARRAY:%.*]], i64 [[I_I64]]
; CHECK-NEXT: [[ARRAY_I:%.*]] = load i32, i32* [[ARRAY_I_PTR]], align 4
; CHECK-NEXT: [[LOOP_ACC_NEXT]] = add i32 [[LOOP_ACC]], [[ARRAY_I]]
; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ult i32 [[I_NEXT]], [[N:%.*]]
; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT2:%.*]] = phi i32 [ [[LOOP_ACC_NEXT]], [[GUARDED2]] ]
; CHECK-NEXT: ret i32 [[RESULT2]]
;
loop.preheader: ; preds = %entry
br label %loop
loop: ; preds = %guarded, %loop.preheader
%loop.acc = phi i32 [ %loop.acc.next, %guarded2 ], [ 0, %loop.preheader ]
%i = phi i32 [ %i.next, %guarded2 ], [ 0, %loop.preheader ]
%within.bounds = icmp ult i32 %i, %length
br i1 %within.bounds, label %guarded, label %deopt, !prof !0
deopt: ; preds = %loop
%result = phi i32 [ %loop.acc, %loop ]
call void @prevent_merging()
ret i32 %result
guarded: ; preds = %loop
%within.bounds2 = icmp ult i32 %i, %length2
br i1 %within.bounds2, label %guarded2, label %deopt2, !prof !0
deopt2: ; preds = %loop
call void @prevent_merging()
ret i32 -1
guarded2: ; preds = %loop
%i.i64 = zext i32 %i to i64
%array.i.ptr = getelementptr inbounds i32, i32* %array, i64 %i.i64
%array.i = load i32, i32* %array.i.ptr, align 4
%loop.acc.next = add i32 %loop.acc, %array.i
%i.next = add nuw i32 %i, 1
%continue = icmp ult i32 %i.next, %n
br i1 %continue, label %loop, label %exit
exit: ; preds = %guarded, %entry
%result2 = phi i32 [ %loop.acc.next, %guarded2 ]
ret i32 %result2
}
declare i32 @llvm.experimental.deoptimize.i32(...)
!0 = !{!"branch_weights", i32 1048576, i32 1}
!1 = !{i32 1, i32 -2147483648}
!2 = !{i32 0, i32 50}
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