smin-smax-folds.ll
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; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
; RUN: opt -analyze -enable-new-pm=0 -scalar-evolution < %s | FileCheck %s
; RUN: opt -disable-output "-passes=print<scalar-evolution>" < %s 2>&1 | FileCheck %s
; Tests for smin & smax folds.
; Test case from PR1614.
define i32 @test_PR1614(i32 %a, i32 %b, i32 %c) {
; CHECK-LABEL: 'test_PR1614'
; CHECK: --> (%a smax %b)
; CHECK: --> (%a smax %b smax %c)
; CHECK-NOT: smax
%A = icmp sgt i32 %a, %b
%B = select i1 %A, i32 %a, i32 %b
%C = icmp sle i32 %c, %B
%D = select i1 %C, i32 %B, i32 %c
ret i32 %D
}
declare void @iteration()
; Test case from PR46939.
; The information from the loop guard can be used to simplify the trip count expression.
define void @smin_simplify_with_guard(i32 %n) {
; CHECK-LABEL: 'smin_simplify_with_guard'
; CHECK-NEXT: Classifying expressions for: @smin_simplify_with_guard
; CHECK-NEXT: %i.011 = phi i32 [ %n, %for.body.lr.ph ], [ %dec, %for.body ]
; CHECK-NEXT: --> {%n,+,-1}<nsw><%for.body> U: full-set S: full-set Exits: 0 LoopDispositions: { %for.body: Computable }
; CHECK-NEXT: %dec = add nsw i32 %i.011, -1
; CHECK-NEXT: --> {(-1 + %n),+,-1}<nw><%for.body> U: full-set S: full-set Exits: -1 LoopDispositions: { %for.body: Computable }
; CHECK-NEXT: Determining loop execution counts for: @smin_simplify_with_guard
; CHECK-NEXT: Loop %for.body: backedge-taken count is %n
; CHECK-NEXT: Loop %for.body: max backedge-taken count is 2147483647
; CHECK-NEXT: Loop %for.body: Predicated backedge-taken count is %n
; CHECK-NEXT: Predicates:
; CHECK: Loop %for.body: Trip multiple is 1
;
entry:
%cmp10 = icmp sgt i32 %n, -1
br i1 %cmp10, label %for.body.lr.ph, label %for.cond.cleanup
for.body.lr.ph:
br label %for.body
for.body:
%i.011 = phi i32 [ %n, %for.body.lr.ph ], [ %dec, %for.body ]
call void @iteration()
%dec = add nsw i32 %i.011, -1
%cmp = icmp sgt i32 %i.011, 0
br i1 %cmp, label %for.body, label %for.cond.cleanup.loopexit
for.cond.cleanup.loopexit:
br label %for.cond.cleanup
for.cond.cleanup:
ret void
}
define void @smin_to_smax(i32 %n) {
; FIXME: ((-1 * (0 smin %n)) + %n) is actually just (0 smax %n)
; CHECK-LABEL: 'smin_to_smax'
; CHECK-NEXT: Classifying expressions for: @smin_to_smax
; CHECK-NEXT: %i.011 = phi i32 [ %n, %for.body.lr.ph ], [ %dec, %for.body ]
; CHECK-NEXT: --> {%n,+,-1}<nsw><%for.body> U: full-set S: full-set Exits: (0 smin %n) LoopDispositions: { %for.body: Computable }
; CHECK-NEXT: %dec = add nsw i32 %i.011, -1
; CHECK-NEXT: --> {(-1 + %n),+,-1}<nw><%for.body> U: full-set S: full-set Exits: (-1 + (0 smin %n)) LoopDispositions: { %for.body: Computable }
; CHECK-NEXT: Determining loop execution counts for: @smin_to_smax
; CHECK-NEXT: Loop %for.body: backedge-taken count is ((-1 * (0 smin %n)) + %n)
; CHECK-NEXT: Loop %for.body: max backedge-taken count is 2147483647
; CHECK-NEXT: Loop %for.body: Predicated backedge-taken count is ((-1 * (0 smin %n)) + %n)
; CHECK-NEXT: Predicates:
; CHECK: Loop %for.body: Trip multiple is 1
;
entry:
br label %for.body.lr.ph
for.body.lr.ph:
br label %for.body
for.body:
%i.011 = phi i32 [ %n, %for.body.lr.ph ], [ %dec, %for.body ]
call void @iteration()
%dec = add nsw i32 %i.011, -1
%cmp = icmp sgt i32 %i.011, 0
br i1 %cmp, label %for.body, label %for.cond.cleanup.loopexit
for.cond.cleanup.loopexit:
br label %for.cond.cleanup
for.cond.cleanup:
ret void
}
; The information from the loop guard can be used to simplify the trip count expression.
define void @smax_simplify_with_guard(i32 %start, i32 %n) {
; CHECK-LABEL: 'smax_simplify_with_guard'
; CHECK-NEXT: Classifying expressions for: @smax_simplify_with_guard
; CHECK-NEXT: %k.0.i26 = phi i32 [ %start, %loop.ph ], [ %inc.i, %loop ]
; CHECK-NEXT: --> {%start,+,1}<nsw><%loop> U: full-set S: full-set Exits: %n LoopDispositions: { %loop: Computable }
; CHECK-NEXT: %inc.i = add nsw i32 %k.0.i26, 1
; CHECK-NEXT: --> {(1 + %start),+,1}<nw><%loop> U: full-set S: full-set Exits: (1 + %n) LoopDispositions: { %loop: Computable }
; CHECK-NEXT: Determining loop execution counts for: @smax_simplify_with_guard
; CHECK-NEXT: Loop %loop: backedge-taken count is ((-1 * %start) + %n)
; CHECK-NEXT: Loop %loop: max backedge-taken count is -1
; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is ((-1 * %start) + %n)
; CHECK-NEXT: Predicates:
; CHECK: Loop %loop: Trip multiple is 1
entry:
%guard = icmp sge i32 %n, %start
br i1 %guard, label %loop.ph, label %exit
loop.ph:
br label %loop
loop:
%k.0.i26 = phi i32 [ %start, %loop.ph ], [ %inc.i, %loop ]
%inc.i = add nsw i32 %k.0.i26, 1
%cmp26.not.i.not = icmp slt i32 %k.0.i26, %n
br i1 %cmp26.not.i.not, label %loop, label %exit
exit:
ret void
}