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https://github.com/RPCS3/llvm-mirror.git
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186e50f9f0
Summary:
Inserting BTI instructions can push branch destinations out of range.
The branch relaxation pass itself cannot insert indirect branches since `TargetInstrInfo::insertIndirecrtBranch` is not implemented for AArch64 (guess +/-128 MB direct branch range is more than enough in practice).
Testing this is a bit tricky.
The original test case we have is 155kloc/6.1M. I've generated a test case using this program:
```
int main() {
std::cout << R"src(int test();
void g0(), g1(), g2(), g3(), g4(), e();
void f(int v) {
if ((test() & 2) == 0) {
switch (v) {
case 0:
g0();
case 1:
g1();
case 2:
g2();
case 3:
g3();
}
)src";
const int N = 8176;
for (int i = 0; i < N; ++i)
std::cout << " void h" << i << "();\n";
for (int i = 0; i < N; ++i)
std::cout << " h" << i << "();\n";
std::cout << R"src(
} else {
e();
}
}
)src";
}
```
which is still a bit too much to commit as a regression test, IMHO.
Reviewers: t.p.northover, ostannard
Reviewed By: ostannard
Subscribers: kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69118
Change-Id: Ide5c922bcde08ff4cf635da5e52365525a997a0a
65 lines
2.5 KiB
LLVM
65 lines
2.5 KiB
LLVM
; RUN: llc %s -o - | FileCheck %s
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target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
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target triple = "aarch64-unknown-unknown-eabi"
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; Function Attrs: nounwind
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define dso_local void @f(i64 %v) local_unnamed_addr #0 {
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entry:
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%call = tail call i32 bitcast (i32 (...)* @test to i32 ()*)() #0
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%and = and i32 %call, 2
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%cmp = icmp eq i32 %and, 0
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br i1 %cmp, label %if.then, label %if.else
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; CHECK: tbz
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; CHECK-NEXT: b
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if.then: ; preds = %entry
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switch i64 %v, label %sw.epilog [
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i64 0, label %sw.bb
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i64 1, label %sw.bb1
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i64 2, label %sw.bb2
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i64 3, label %sw.bb3
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]
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sw.bb: ; preds = %if.then
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tail call void bitcast (void (...)* @g0 to void ()*)() #0
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br label %sw.bb1
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sw.bb1: ; preds = %if.then, %sw.bb
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tail call void bitcast (void (...)* @g1 to void ()*)() #0
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br label %sw.bb2
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sw.bb2: ; preds = %if.then, %sw.bb1
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tail call void bitcast (void (...)* @g2 to void ()*)() #0
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br label %sw.bb3
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sw.bb3: ; preds = %if.then, %sw.bb2
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tail call void bitcast (void (...)* @g3 to void ()*)() #0
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br label %sw.epilog
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sw.epilog: ; preds = %sw.bb3, %if.then
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%dummy = tail call i64 @llvm.aarch64.space(i32 32700, i64 %v)
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br label %if.end
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if.else: ; preds = %entry
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tail call void bitcast (void (...)* @e to void ()*)() #0
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br label %if.end
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if.end: ; preds = %if.else, %sw.epilog
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ret void
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}
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declare dso_local i32 @test(...) local_unnamed_addr #0
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declare dso_local void @g0(...) local_unnamed_addr #0
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declare dso_local void @g1(...) local_unnamed_addr #0
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declare dso_local void @g2(...) local_unnamed_addr #0
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declare dso_local void @g3(...) local_unnamed_addr #0
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declare dso_local void @e(...) local_unnamed_addr #0
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declare dso_local i64 @llvm.aarch64.space(i32, i64) local_unnamed_addr #0
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attributes #0 = { nounwind "branch-target-enforcement" "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+neon,+v8.5a" "unsafe-fp-math"="false" "use-soft-float"="false" }
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