; RUN: opt -S -licm < %s | FileCheck %s
; UDiv is safe to speculate if the denominator is known non-zero.
; CHECK: @safe_udiv
; CHECK: %div = udiv i64 %x, %or
; CHECK-NEXT: br label %for.body
define void @safe_udiv(i64 %x, i64 %m, i64 %n, i32* %p, i64* %q) nounwind {
entry:
%or = or i64 %m, 1
br label %for.body
for.body: ; preds = %entry, %for.inc
%i.02 = phi i64 [ %inc, %for.inc ], [ 0, %entry ]
%arrayidx = getelementptr inbounds i32* %p, i64 %i.02
%0 = load i32* %arrayidx, align 4
%tobool = icmp eq i32 %0, 0
br i1 %tobool, label %for.inc, label %if.then
if.then: ; preds = %for.body
%div = udiv i64 %x, %or
%arrayidx1 = getelementptr inbounds i64* %q, i64 %i.02
store i64 %div, i64* %arrayidx1, align 8
br label %for.inc
for.inc: ; preds = %if.then, %for.body
%inc = add i64 %i.02, 1
%cmp = icmp slt i64 %inc, %n
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.inc, %entry
ret void
}
; UDiv is unsafe to speculate if the denominator is not known non-zero.
; CHECK: @unsafe_udiv
; CHECK-NOT: udiv
; CHECK: for.body:
define void @unsafe_udiv(i64 %x, i64 %m, i64 %n, i32* %p, i64* %q) nounwind {
entry:
br label %for.body
for.body: ; preds = %entry, %for.inc
%i.02 = phi i64 [ %inc, %for.inc ], [ 0, %entry ]
%arrayidx = getelementptr inbounds i32* %p, i64 %i.02
%0 = load i32* %arrayidx, align 4
%tobool = icmp eq i32 %0, 0
br i1 %tobool, label %for.inc, label %if.then
if.then: ; preds = %for.body
%div = udiv i64 %x, %m
%arrayidx1 = getelementptr inbounds i64* %q, i64 %i.02
store i64 %div, i64* %arrayidx1, align 8
br label %for.inc
for.inc: ; preds = %if.then, %for.body
%inc = add i64 %i.02, 1
%cmp = icmp slt i64 %inc, %n
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.inc, %entry
ret void
}
; SDiv is safe to speculate if the denominator is known non-zero and
; known to have at least one zero bit.
; CHECK: @safe_sdiv
; CHECK: %div = sdiv i64 %x, %or
; CHECK-NEXT: br label %for.body
define void @safe_sdiv(i64 %x, i64 %m, i64 %n, i32* %p, i64* %q) nounwind {
entry:
%and = and i64 %m, -3
%or = or i64 %and, 1
br label %for.body
for.body: ; preds = %entry, %for.inc
%i.02 = phi i64 [ %inc, %for.inc ], [ 0, %entry ]
%arrayidx = getelementptr inbounds i32* %p, i64 %i.02
%0 = load i32* %arrayidx, align 4
%tobool = icmp eq i32 %0, 0
br i1 %tobool, label %for.inc, label %if.then
if.then: ; preds = %for.body
%div = sdiv i64 %x, %or
%arrayidx1 = getelementptr inbounds i64* %q, i64 %i.02
store i64 %div, i64* %arrayidx1, align 8
br label %for.inc
for.inc: ; preds = %if.then, %for.body
%inc = add i64 %i.02, 1
%cmp = icmp slt i64 %inc, %n
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.inc, %entry
ret void
}
; SDiv is unsafe to speculate if the denominator is not known non-zero.
; CHECK: @unsafe_sdiv_a
; CHECK-NOT: sdiv
; CHECK: for.body:
define void @unsafe_sdiv_a(i64 %x, i64 %m, i64 %n, i32* %p, i64* %q) nounwind {
entry:
%or = or i64 %m, 1
br label %for.body
for.body: ; preds = %entry, %for.inc
%i.02 = phi i64 [ %inc, %for.inc ], [ 0, %entry ]
%arrayidx = getelementptr inbounds i32* %p, i64 %i.02
%0 = load i32* %arrayidx, align 4
%tobool = icmp eq i32 %0, 0
br i1 %tobool, label %for.inc, label %if.then
if.then: ; preds = %for.body
%div = sdiv i64 %x, %or
%arrayidx1 = getelementptr inbounds i64* %q, i64 %i.02
store i64 %div, i64* %arrayidx1, align 8
br label %for.inc
for.inc: ; preds = %if.then, %for.body
%inc = add i64 %i.02, 1
%cmp = icmp slt i64 %inc, %n
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.inc, %entry
ret void
}
; SDiv is unsafe to speculate if the denominator is not known to have a zero bit.
; CHECK: @unsafe_sdiv_b
; CHECK-NOT: sdiv
; CHECK: for.body:
define void @unsafe_sdiv_b(i64 %x, i64 %m, i64 %n, i32* %p, i64* %q) nounwind {
entry:
%and = and i64 %m, -3
br label %for.body
for.body: ; preds = %entry, %for.inc
%i.02 = phi i64 [ %inc, %for.inc ], [ 0, %entry ]
%arrayidx = getelementptr inbounds i32* %p, i64 %i.02
%0 = load i32* %arrayidx, align 4
%tobool = icmp eq i32 %0, 0
br i1 %tobool, label %for.inc, label %if.then
if.then: ; preds = %for.body
%div = sdiv i64 %x, %and
%arrayidx1 = getelementptr inbounds i64* %q, i64 %i.02
store i64 %div, i64* %arrayidx1, align 8
br label %for.inc
for.inc: ; preds = %if.then, %for.body
%inc = add i64 %i.02, 1
%cmp = icmp slt i64 %inc, %n
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.inc, %entry
ret void
}
; SDiv is unsafe to speculate inside an infinite loop.
define void @unsafe_sdiv_c(i64 %a, i64 %b, i64* %p) {
entry:
; CHECK: entry:
; CHECK-NOT: sdiv
; CHECK: br label %for.body
br label %for.body
for.body:
%c = icmp eq i64 %b, 0
br i1 %c, label %backedge, label %if.then
if.then:
%d = sdiv i64 %a, %b
store i64 %d, i64* %p
br label %backedge
backedge:
br label %for.body
}