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https://github.com/c64scene-ar/llvm-6502.git
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148e8c9b8b
IRCE eliminates range checks of the form
0 <= A * I + B < Length
by splitting a loop's iteration space into three segments in a way
that the check is completely redundant in the middle segment. As an
example, IRCE will convert
len = < known positive >
for (i = 0; i < n; i++) {
if (0 <= i && i < len) {
do_something();
} else {
throw_out_of_bounds();
}
}
to
len = < known positive >
limit = smin(n, len)
// no first segment
for (i = 0; i < limit; i++) {
if (0 <= i && i < len) { // this check is fully redundant
do_something();
} else {
throw_out_of_bounds();
}
}
for (i = limit; i < n; i++) {
if (0 <= i && i < len) {
do_something();
} else {
throw_out_of_bounds();
}
}
IRCE can deal with multiple range checks in the same loop (it takes
the intersection of the ranges that will make each of them redundant
individually).
Currently IRCE does not do any profitability analysis. That is a
TODO.
Please note that the status of this pass is *experimental*, and it is
not part of any default pass pipeline. Having said that, I will love
to get feedback and general input from people interested in trying
this out.
This pass was originally r226201. It was reverted because it used C++
features not supported by MSVC 2012.
Differential Revision: http://reviews.llvm.org/D6693
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226238 91177308-0d34-0410-b5e6-96231b3b80d8
345 lines
14 KiB
LLVM
345 lines
14 KiB
LLVM
; RUN: opt -verify-loop-info -irce-print-changed-loops -irce < %s 2>&1 | FileCheck %s
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; This test checks if we update the LoopInfo correctly in the presence
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; of parents, uncles and cousins.
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; Function Attrs: alwaysinline
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define void @inner_loop(i32* %arr, i32* %a_len_ptr, i32 %n) #0 {
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; CHECK: irce: in function inner_loop: constrained Loop at depth 1 containing: %loop<header><exiting>,%in.bounds<latch><exiting>
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entry:
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%len = load i32* %a_len_ptr, !range !0
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%first.itr.check = icmp sgt i32 %n, 0
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br i1 %first.itr.check, label %loop, label %exit
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loop: ; preds = %in.bounds, %entry
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%idx = phi i32 [ 0, %entry ], [ %idx.next, %in.bounds ]
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%idx.next = add i32 %idx, 1
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%abc = icmp slt i32 %idx, %len
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br i1 %abc, label %in.bounds, label %out.of.bounds
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in.bounds: ; preds = %loop
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%addr = getelementptr i32* %arr, i32 %idx
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store i32 0, i32* %addr
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%next = icmp slt i32 %idx.next, %n
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br i1 %next, label %loop, label %exit
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out.of.bounds: ; preds = %loop
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ret void
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exit: ; preds = %in.bounds, %entry
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ret void
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}
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; Function Attrs: alwaysinline
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define void @with_parent(i32* %arr, i32* %a_len_ptr, i32 %n, i32 %parent.count) #0 {
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; CHECK: irce: in function with_parent: constrained Loop at depth 2 containing: %loop.i<header><exiting>,%in.bounds.i<latch><exiting>
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entry:
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br label %loop
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loop: ; preds = %inner_loop.exit, %entry
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%idx = phi i32 [ 0, %entry ], [ %idx.next, %inner_loop.exit ]
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%idx.next = add i32 %idx, 1
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%next = icmp ult i32 %idx.next, %parent.count
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%len.i = load i32* %a_len_ptr, !range !0
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%first.itr.check.i = icmp sgt i32 %n, 0
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br i1 %first.itr.check.i, label %loop.i, label %exit.i
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loop.i: ; preds = %in.bounds.i, %loop
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%idx.i = phi i32 [ 0, %loop ], [ %idx.next.i, %in.bounds.i ]
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%idx.next.i = add i32 %idx.i, 1
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%abc.i = icmp slt i32 %idx.i, %len.i
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br i1 %abc.i, label %in.bounds.i, label %out.of.bounds.i
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in.bounds.i: ; preds = %loop.i
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%addr.i = getelementptr i32* %arr, i32 %idx.i
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store i32 0, i32* %addr.i
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%next.i = icmp slt i32 %idx.next.i, %n
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br i1 %next.i, label %loop.i, label %exit.i
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out.of.bounds.i: ; preds = %loop.i
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br label %inner_loop.exit
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exit.i: ; preds = %in.bounds.i, %loop
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br label %inner_loop.exit
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inner_loop.exit: ; preds = %exit.i, %out.of.bounds.i
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br i1 %next, label %loop, label %exit
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exit: ; preds = %inner_loop.exit
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ret void
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}
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; Function Attrs: alwaysinline
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define void @with_grandparent(i32* %arr, i32* %a_len_ptr, i32 %n, i32 %parent.count, i32 %grandparent.count) #0 {
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; CHECK: irce: in function with_grandparent: constrained Loop at depth 3 containing: %loop.i.i<header><exiting>,%in.bounds.i.i<latch><exiting>
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entry:
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br label %loop
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loop: ; preds = %with_parent.exit, %entry
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%idx = phi i32 [ 0, %entry ], [ %idx.next, %with_parent.exit ]
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%idx.next = add i32 %idx, 1
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%next = icmp ult i32 %idx.next, %grandparent.count
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br label %loop.i
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loop.i: ; preds = %inner_loop.exit.i, %loop
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%idx.i = phi i32 [ 0, %loop ], [ %idx.next.i, %inner_loop.exit.i ]
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%idx.next.i = add i32 %idx.i, 1
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%next.i = icmp ult i32 %idx.next.i, %parent.count
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%len.i.i = load i32* %a_len_ptr, !range !0
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%first.itr.check.i.i = icmp sgt i32 %n, 0
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br i1 %first.itr.check.i.i, label %loop.i.i, label %exit.i.i
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loop.i.i: ; preds = %in.bounds.i.i, %loop.i
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%idx.i.i = phi i32 [ 0, %loop.i ], [ %idx.next.i.i, %in.bounds.i.i ]
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%idx.next.i.i = add i32 %idx.i.i, 1
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%abc.i.i = icmp slt i32 %idx.i.i, %len.i.i
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br i1 %abc.i.i, label %in.bounds.i.i, label %out.of.bounds.i.i
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in.bounds.i.i: ; preds = %loop.i.i
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%addr.i.i = getelementptr i32* %arr, i32 %idx.i.i
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store i32 0, i32* %addr.i.i
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%next.i.i = icmp slt i32 %idx.next.i.i, %n
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br i1 %next.i.i, label %loop.i.i, label %exit.i.i
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out.of.bounds.i.i: ; preds = %loop.i.i
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br label %inner_loop.exit.i
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exit.i.i: ; preds = %in.bounds.i.i, %loop.i
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br label %inner_loop.exit.i
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inner_loop.exit.i: ; preds = %exit.i.i, %out.of.bounds.i.i
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br i1 %next.i, label %loop.i, label %with_parent.exit
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with_parent.exit: ; preds = %inner_loop.exit.i
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br i1 %next, label %loop, label %exit
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exit: ; preds = %with_parent.exit
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ret void
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}
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; Function Attrs: alwaysinline
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define void @with_sibling(i32* %arr, i32* %a_len_ptr, i32 %n, i32 %parent.count) #0 {
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; CHECK: irce: in function with_sibling: constrained Loop at depth 2 containing: %loop.i<header><exiting>,%in.bounds.i<latch><exiting>
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; CHECK: irce: in function with_sibling: constrained Loop at depth 2 containing: %loop.i6<header><exiting>,%in.bounds.i9<latch><exiting>
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entry:
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br label %loop
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loop: ; preds = %inner_loop.exit12, %entry
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%idx = phi i32 [ 0, %entry ], [ %idx.next, %inner_loop.exit12 ]
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%idx.next = add i32 %idx, 1
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%next = icmp ult i32 %idx.next, %parent.count
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%len.i = load i32* %a_len_ptr, !range !0
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%first.itr.check.i = icmp sgt i32 %n, 0
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br i1 %first.itr.check.i, label %loop.i, label %exit.i
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loop.i: ; preds = %in.bounds.i, %loop
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%idx.i = phi i32 [ 0, %loop ], [ %idx.next.i, %in.bounds.i ]
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%idx.next.i = add i32 %idx.i, 1
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%abc.i = icmp slt i32 %idx.i, %len.i
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br i1 %abc.i, label %in.bounds.i, label %out.of.bounds.i
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in.bounds.i: ; preds = %loop.i
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%addr.i = getelementptr i32* %arr, i32 %idx.i
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store i32 0, i32* %addr.i
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%next.i = icmp slt i32 %idx.next.i, %n
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br i1 %next.i, label %loop.i, label %exit.i
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out.of.bounds.i: ; preds = %loop.i
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br label %inner_loop.exit
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exit.i: ; preds = %in.bounds.i, %loop
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br label %inner_loop.exit
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inner_loop.exit: ; preds = %exit.i, %out.of.bounds.i
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%len.i1 = load i32* %a_len_ptr, !range !0
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%first.itr.check.i2 = icmp sgt i32 %n, 0
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br i1 %first.itr.check.i2, label %loop.i6, label %exit.i11
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loop.i6: ; preds = %in.bounds.i9, %inner_loop.exit
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%idx.i3 = phi i32 [ 0, %inner_loop.exit ], [ %idx.next.i4, %in.bounds.i9 ]
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%idx.next.i4 = add i32 %idx.i3, 1
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%abc.i5 = icmp slt i32 %idx.i3, %len.i1
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br i1 %abc.i5, label %in.bounds.i9, label %out.of.bounds.i10
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in.bounds.i9: ; preds = %loop.i6
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%addr.i7 = getelementptr i32* %arr, i32 %idx.i3
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store i32 0, i32* %addr.i7
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%next.i8 = icmp slt i32 %idx.next.i4, %n
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br i1 %next.i8, label %loop.i6, label %exit.i11
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out.of.bounds.i10: ; preds = %loop.i6
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br label %inner_loop.exit12
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exit.i11: ; preds = %in.bounds.i9, %inner_loop.exit
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br label %inner_loop.exit12
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inner_loop.exit12: ; preds = %exit.i11, %out.of.bounds.i10
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br i1 %next, label %loop, label %exit
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exit: ; preds = %inner_loop.exit12
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ret void
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}
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; Function Attrs: alwaysinline
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define void @with_cousin(i32* %arr, i32* %a_len_ptr, i32 %n, i32 %parent.count, i32 %grandparent.count) #0 {
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; CHECK: irce: in function with_cousin: constrained Loop at depth 3 containing: %loop.i.i<header><exiting>,%in.bounds.i.i<latch><exiting>
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; CHECK: irce: in function with_cousin: constrained Loop at depth 3 containing: %loop.i.i10<header><exiting>,%in.bounds.i.i13<latch><exiting>
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entry:
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br label %loop
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loop: ; preds = %with_parent.exit17, %entry
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%idx = phi i32 [ 0, %entry ], [ %idx.next, %with_parent.exit17 ]
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%idx.next = add i32 %idx, 1
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%next = icmp ult i32 %idx.next, %grandparent.count
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br label %loop.i
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loop.i: ; preds = %inner_loop.exit.i, %loop
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%idx.i = phi i32 [ 0, %loop ], [ %idx.next.i, %inner_loop.exit.i ]
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%idx.next.i = add i32 %idx.i, 1
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%next.i = icmp ult i32 %idx.next.i, %parent.count
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%len.i.i = load i32* %a_len_ptr, !range !0
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%first.itr.check.i.i = icmp sgt i32 %n, 0
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br i1 %first.itr.check.i.i, label %loop.i.i, label %exit.i.i
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loop.i.i: ; preds = %in.bounds.i.i, %loop.i
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%idx.i.i = phi i32 [ 0, %loop.i ], [ %idx.next.i.i, %in.bounds.i.i ]
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%idx.next.i.i = add i32 %idx.i.i, 1
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%abc.i.i = icmp slt i32 %idx.i.i, %len.i.i
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br i1 %abc.i.i, label %in.bounds.i.i, label %out.of.bounds.i.i
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in.bounds.i.i: ; preds = %loop.i.i
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%addr.i.i = getelementptr i32* %arr, i32 %idx.i.i
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store i32 0, i32* %addr.i.i
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%next.i.i = icmp slt i32 %idx.next.i.i, %n
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br i1 %next.i.i, label %loop.i.i, label %exit.i.i
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out.of.bounds.i.i: ; preds = %loop.i.i
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br label %inner_loop.exit.i
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exit.i.i: ; preds = %in.bounds.i.i, %loop.i
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br label %inner_loop.exit.i
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inner_loop.exit.i: ; preds = %exit.i.i, %out.of.bounds.i.i
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br i1 %next.i, label %loop.i, label %with_parent.exit
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with_parent.exit: ; preds = %inner_loop.exit.i
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br label %loop.i6
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loop.i6: ; preds = %inner_loop.exit.i16, %with_parent.exit
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%idx.i1 = phi i32 [ 0, %with_parent.exit ], [ %idx.next.i2, %inner_loop.exit.i16 ]
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%idx.next.i2 = add i32 %idx.i1, 1
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%next.i3 = icmp ult i32 %idx.next.i2, %parent.count
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%len.i.i4 = load i32* %a_len_ptr, !range !0
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%first.itr.check.i.i5 = icmp sgt i32 %n, 0
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br i1 %first.itr.check.i.i5, label %loop.i.i10, label %exit.i.i15
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loop.i.i10: ; preds = %in.bounds.i.i13, %loop.i6
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%idx.i.i7 = phi i32 [ 0, %loop.i6 ], [ %idx.next.i.i8, %in.bounds.i.i13 ]
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%idx.next.i.i8 = add i32 %idx.i.i7, 1
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%abc.i.i9 = icmp slt i32 %idx.i.i7, %len.i.i4
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br i1 %abc.i.i9, label %in.bounds.i.i13, label %out.of.bounds.i.i14
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in.bounds.i.i13: ; preds = %loop.i.i10
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%addr.i.i11 = getelementptr i32* %arr, i32 %idx.i.i7
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store i32 0, i32* %addr.i.i11
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%next.i.i12 = icmp slt i32 %idx.next.i.i8, %n
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br i1 %next.i.i12, label %loop.i.i10, label %exit.i.i15
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out.of.bounds.i.i14: ; preds = %loop.i.i10
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br label %inner_loop.exit.i16
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exit.i.i15: ; preds = %in.bounds.i.i13, %loop.i6
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br label %inner_loop.exit.i16
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inner_loop.exit.i16: ; preds = %exit.i.i15, %out.of.bounds.i.i14
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br i1 %next.i3, label %loop.i6, label %with_parent.exit17
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with_parent.exit17: ; preds = %inner_loop.exit.i16
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br i1 %next, label %loop, label %exit
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exit: ; preds = %with_parent.exit17
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ret void
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}
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; Function Attrs: alwaysinline
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define void @with_uncle(i32* %arr, i32* %a_len_ptr, i32 %n, i32 %parent.count, i32 %grandparent.count) #0 {
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; CHECK: irce: in function with_uncle: constrained Loop at depth 2 containing: %loop.i<header><exiting>,%in.bounds.i<latch><exiting>
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; CHECK: irce: in function with_uncle: constrained Loop at depth 3 containing: %loop.i.i<header><exiting>,%in.bounds.i.i<latch><exiting>
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entry:
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br label %loop
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loop: ; preds = %with_parent.exit, %entry
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%idx = phi i32 [ 0, %entry ], [ %idx.next, %with_parent.exit ]
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%idx.next = add i32 %idx, 1
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%next = icmp ult i32 %idx.next, %grandparent.count
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%len.i = load i32* %a_len_ptr, !range !0
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%first.itr.check.i = icmp sgt i32 %n, 0
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br i1 %first.itr.check.i, label %loop.i, label %exit.i
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loop.i: ; preds = %in.bounds.i, %loop
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%idx.i = phi i32 [ 0, %loop ], [ %idx.next.i, %in.bounds.i ]
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%idx.next.i = add i32 %idx.i, 1
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%abc.i = icmp slt i32 %idx.i, %len.i
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br i1 %abc.i, label %in.bounds.i, label %out.of.bounds.i
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in.bounds.i: ; preds = %loop.i
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%addr.i = getelementptr i32* %arr, i32 %idx.i
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store i32 0, i32* %addr.i
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%next.i = icmp slt i32 %idx.next.i, %n
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br i1 %next.i, label %loop.i, label %exit.i
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out.of.bounds.i: ; preds = %loop.i
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br label %inner_loop.exit
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exit.i: ; preds = %in.bounds.i, %loop
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br label %inner_loop.exit
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inner_loop.exit: ; preds = %exit.i, %out.of.bounds.i
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br label %loop.i4
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loop.i4: ; preds = %inner_loop.exit.i, %inner_loop.exit
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%idx.i1 = phi i32 [ 0, %inner_loop.exit ], [ %idx.next.i2, %inner_loop.exit.i ]
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%idx.next.i2 = add i32 %idx.i1, 1
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%next.i3 = icmp ult i32 %idx.next.i2, %parent.count
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%len.i.i = load i32* %a_len_ptr, !range !0
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%first.itr.check.i.i = icmp sgt i32 %n, 0
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br i1 %first.itr.check.i.i, label %loop.i.i, label %exit.i.i
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loop.i.i: ; preds = %in.bounds.i.i, %loop.i4
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%idx.i.i = phi i32 [ 0, %loop.i4 ], [ %idx.next.i.i, %in.bounds.i.i ]
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%idx.next.i.i = add i32 %idx.i.i, 1
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%abc.i.i = icmp slt i32 %idx.i.i, %len.i.i
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br i1 %abc.i.i, label %in.bounds.i.i, label %out.of.bounds.i.i
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in.bounds.i.i: ; preds = %loop.i.i
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%addr.i.i = getelementptr i32* %arr, i32 %idx.i.i
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store i32 0, i32* %addr.i.i
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%next.i.i = icmp slt i32 %idx.next.i.i, %n
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br i1 %next.i.i, label %loop.i.i, label %exit.i.i
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out.of.bounds.i.i: ; preds = %loop.i.i
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br label %inner_loop.exit.i
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exit.i.i: ; preds = %in.bounds.i.i, %loop.i4
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br label %inner_loop.exit.i
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inner_loop.exit.i: ; preds = %exit.i.i, %out.of.bounds.i.i
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br i1 %next.i3, label %loop.i4, label %with_parent.exit
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with_parent.exit: ; preds = %inner_loop.exit.i
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br i1 %next, label %loop, label %exit
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exit: ; preds = %with_parent.exit
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ret void
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|
}
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attributes #0 = { alwaysinline }
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!0 = !{i32 0, i32 2147483647}
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