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; RUN: opt -S -analyze -scalar-evolution < %s 2>&1 | FileCheck %s
; umin is represented using -1 * umax in scalar evolution. -1 is considered as the
; constant of the multiply expression (-1 * ((-1 + (-1 * %a)) umax (-1 + (-1 * %b)))).
; Returns the greatest power of 2 divisor by evaluating the minimal trailing zeros
; for the trip count expression.
;
; int foo(uint32_t a, uint32_t b, uint32_t *c) {
; for (uint32_t i = 0; i < (uint32_t)(a < b ? a : b) + 1; i++)
; c[i] = i;
; return 0;
; }
;
; CHECK: Loop %for.body: Trip multiple is 1
define i32 @foo(i32 %a, i32 %b, i32* %c) {
entry:
%cmp = icmp ult i32 %a, %b
%cond = select i1 %cmp, i32 %a, i32 %b
%add = add i32 %cond, 1
%cmp18 = icmp eq i32 %add, 0
br i1 %cmp18, label %for.cond.cleanup, label %for.body.preheader
for.body.preheader: ; preds = %entry
br label %for.body
for.cond.cleanup.loopexit: ; preds = %for.body
br label %for.cond.cleanup
for.cond.cleanup: ; preds = %for.cond.cleanup.loopexit, %entry
ret i32 0
for.body: ; preds = %for.body.preheader, %for.body
%i.09 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
%arrayidx = getelementptr inbounds i32, i32* %c, i32 %i.09
store i32 %i.09, i32* %arrayidx, align 4
%inc = add nuw i32 %i.09, 1
%cmp1 = icmp ult i32 %inc, %add
br i1 %cmp1, label %for.body, label %for.cond.cleanup.loopexit
}
; Overflow may happen for the multiply expression n * 3, verify that trip
; multiple is set to 1 if NUW/NSW are not set.
;
; __attribute__((noinline)) void a(unsigned n) {
; #pragma unroll(3)
; for (unsigned i = 0; i != n * 3; ++i)
; printf("TEST%u\n", i);
; }
; int main() { a(2863311531U); }
;
; CHECK: Loop %for.body: Trip multiple is 1
@.str2 = private unnamed_addr constant [8 x i8] c"TEST%u\0A\00", align 1
define void @foo2(i32 %n) {
entry:
%mul = mul i32 %n, 3
%cmp4 = icmp eq i32 %mul, 0
br i1 %cmp4, label %for.cond.cleanup, label %for.body.preheader
for.body.preheader: ; preds = %entry
br label %for.body
for.cond.cleanup.loopexit: ; preds = %for.body
br label %for.cond.cleanup
for.cond.cleanup: ; preds = %for.cond.cleanup.loopexit, %entry
ret void
for.body: ; preds = %for.body.preheader, %for.body
%i.05 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
%call = tail call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str2, i32 0, i32 0), i32 %i.05)
%inc = add nuw i32 %i.05, 1
%cmp = icmp eq i32 %inc, %mul
br i1 %cmp, label %for.cond.cleanup.loopexit, label %for.body
}
declare i32 @printf(i8* nocapture readonly, ...)
; If we couldn't prove no overflow for the multiply expression 24 * n,
; returns the greatest power of 2 divisor. If overflows happens
; the trip count is still divisible by the greatest power of 2 divisor.
;
; CHECK: Loop %l3: Trip multiple is 8
declare void @f()
define i32 @foo3(i32 %n) {
entry:
%loop_ctl = mul i32 %n, 24
br label %l3
l3:
%x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
call void @f()
%inc = add i32 %x.0, 1
%exitcond = icmp eq i32 %inc, %loop_ctl
br i1 %exitcond, label %exit, label %l3
exit:
ret i32 0
}
; If the trip count is a constant, verify that we obtained the trip
; count itself. For huge trip counts, or zero, we return 1.
;
; CHECK: Loop %l3: Trip multiple is 3
define i32 @foo4(i32 %n) {
entry:
br label %l3
l3:
%x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
call void @f()
%inc = add i32 %x.0, 1
%exitcond = icmp eq i32 %inc, 3
br i1 %exitcond, label %exit, label %l3
exit:
ret i32 0
}
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