smax-br-phi-idioms.ll
3.43 KB
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; RUN: opt -analyze -scalar-evolution < %s | FileCheck %s
define i32 @f0(i32 %x, i32 %y) {
; CHECK-LABEL: Classifying expressions for: @f0
entry:
%c = icmp sgt i32 %y, 0
br i1 %c, label %add, label %merge
add:
%sum = add i32 %x, %y
br label %merge
merge:
%v = phi i32 [ %sum, %add ], [ %x, %entry ]
; CHECK: %v = phi i32 [ %sum, %add ], [ %x, %entry ]
; CHECK-NEXT: --> ((0 smax %y) + %x) U: full-set S: full-set
ret i32 %v
}
define i32 @f1(i32 %x, i32 %y) {
; CHECK-LABEL: Classifying expressions for: @f1
entry:
%c = icmp sge i32 %y, 0
br i1 %c, label %add, label %merge
add:
%sum = add i32 %x, %y
br label %merge
merge:
%v = phi i32 [ %sum, %add ], [ %x, %entry ]
; CHECK: %v = phi i32 [ %sum, %add ], [ %x, %entry ]
; CHECK-NEXT: --> ((0 smax %y) + %x) U: full-set S: full-set
ret i32 %v
}
define i32 @f2(i32 %x, i32 %y, i32* %ptr) {
; CHECK-LABEL: Classifying expressions for: @f2
entry:
%c = icmp sge i32 %y, 0
br i1 %c, label %add, label %merge
add:
%lv = load i32, i32* %ptr
br label %merge
merge:
%v = phi i32 [ %lv, %add ], [ %x, %entry ]
; CHECK: %v = phi i32 [ %lv, %add ], [ %x, %entry ]
; CHECK-NEXT: --> %v U: full-set S: full-set
ret i32 %v
}
define i32 @f3(i32 %x, i32 %init, i32 %lim) {
; CHECK-LABEL: Classifying expressions for: @f3
entry:
br label %loop
loop:
%iv = phi i32 [ %init, %entry ], [ %iv.inc, %merge ]
%iv.inc = add i32 %iv, 1
%c = icmp sge i32 %iv, 0
br i1 %c, label %add, label %merge
add:
%sum = add i32 %x, %iv
br label %merge
merge:
%v = phi i32 [ %sum, %add ], [ %x, %loop ]
; CHECK: %v = phi i32 [ %sum, %add ], [ %x, %loop ]
; CHECK-NEXT: --> ((0 smax {%init,+,1}<%loop>) + %x) U: full-set S: full-set
%be.cond = icmp eq i32 %iv.inc, %lim
br i1 %be.cond, label %loop, label %leave
leave:
ret i32 0
}
define i32 @f4(i32 %x, i32 %init, i32 %lim) {
; CHECK-LABEL: Classifying expressions for: @f4
entry:
%c = icmp sge i32 %init, 0
br i1 %c, label %add, label %merge
add:
br label %loop
loop:
%iv = phi i32 [ %init, %add ], [ %iv.inc, %loop ]
%iv.inc = add i32 %iv, 1
%be.cond = icmp eq i32 %iv.inc, %lim
br i1 %be.cond, label %loop, label %add.cont
add.cont:
%sum = add i32 %x, %iv
br label %merge
merge:
%v = phi i32 [ %sum, %add.cont ], [ %x, %entry ]
; CHECK: %v = phi i32 [ %sum, %add.cont ], [ %x, %entry ]
; CHECK-NEXT: --> %v U: full-set S: full-set
ret i32 %v
}
define i32 @f5(i32* %val) {
; CHECK-LABEL: Classifying expressions for: @f5
entry:
br label %for.end
for.condt:
br i1 true, label %for.cond.0, label %for.end
for.end:
%inc = load i32, i32* %val
br i1 false, label %for.condt, label %for.cond.0
for.cond.0:
%init = phi i32 [ 0, %for.condt ], [ %inc, %for.end ]
; CHECK: %init = phi i32 [ 0, %for.condt ], [ %inc, %for.end ]
; CHECK-NEXT: --> %init U: full-set S: full-set
; Matching "through" %init will break LCSSA at the SCEV expression
; level.
ret i32 %init
}
define i32 @f6(i32 %x, i32 %y) {
; Do the right thing for unreachable code:
; CHECK-LABEL: Classifying expressions for: @f6
entry:
%c0 = icmp sgt i32 %y, 0
%sum = add i32 %x, %y
br i1 %c0, label %merge, label %leave_1
merge:
%v0 = phi i32 [ %sum, %entry ], [ %v1, %unreachable ]
%c1 = icmp slt i32 %y, 0
br i1 %c1, label %leave_0, label %leave_0_cond
leave_0_cond:
br label %leave_0
leave_0:
%v1 = phi i32 [ %v0, %merge ], [ 0, %leave_0_cond ]
ret i32 0
leave_1:
ret i32 0
unreachable:
br label %merge
}