d3b522f519
Commit 37962a331c77 ("bpf: Improve expanding logic in LowerSELECT_CC")
intended to improve code quality for certain jmp conditions. The
commit, however, has a couple of issues:
(1). In code, just swap is not enough, ConditionalCode CC
should also be swapped, otherwise incorrect code will
be generated.
(2). The ConditionalCode swap should be subject to
getHasJmpExt(). If getHasJmpExt() is False, certain
conditional codes will not be supported and swap
may generate incorrect code.
The original goal for this patch is to optimize jmp operations
which does not have JmpExt turned on. If JmpExt is on,
better code could be generated. For example, the test
select_ri.ll is introduced to demonstrate the optimization.
The same result can be achieved with -mcpu=v2 flag.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 329043
120 lines
3.0 KiB
LLVM
120 lines
3.0 KiB
LLVM
; RUN: llc < %s -march=bpf | FileCheck %s
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; Function Attrs: nounwind readnone uwtable
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define signext i8 @foo_cmp1(i8 signext %a, i8 signext %b) #0 {
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%1 = icmp sgt i8 %a, %b
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br i1 %1, label %2, label %4
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; <label>:2 ; preds = %0
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%3 = mul i8 %b, %a
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br label %6
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; <label>:4 ; preds = %0
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%5 = shl i8 %b, 3
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br label %6
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; <label>:6 ; preds = %4, %2
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%.0 = phi i8 [ %3, %2 ], [ %5, %4 ]
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ret i8 %.0
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; CHECK-LABEL:foo_cmp1:
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; CHECK: if r0 s>= r1
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}
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; Function Attrs: nounwind readnone uwtable
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define signext i8 @foo_cmp2(i8 signext %a, i8 signext %b) #0 {
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%1 = icmp slt i8 %a, %b
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br i1 %1, label %4, label %2
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; <label>:2 ; preds = %0
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%3 = mul i8 %b, %a
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br label %6
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; <label>:4 ; preds = %0
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%5 = shl i8 %b, 3
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br label %6
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; <label>:6 ; preds = %4, %2
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%.0 = phi i8 [ %3, %2 ], [ %5, %4 ]
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ret i8 %.0
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; CHECK-LABEL:foo_cmp2:
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; CHECK: if r0 s> r1
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}
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; Function Attrs: nounwind readnone uwtable
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define signext i8 @foo_cmp3(i8 signext %a, i8 signext %b) #0 {
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%1 = icmp slt i8 %a, %b
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br i1 %1, label %2, label %4
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; <label>:2 ; preds = %0
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%3 = mul i8 %b, %a
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br label %6
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; <label>:4 ; preds = %0
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%5 = shl i8 %b, 3
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br label %6
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; <label>:6 ; preds = %4, %2
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%.0 = phi i8 [ %3, %2 ], [ %5, %4 ]
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ret i8 %.0
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; CHECK-LABEL:foo_cmp3:
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; CHECK: if r1 s>= r0
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}
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; Function Attrs: nounwind readnone uwtable
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define signext i8 @foo_cmp4(i8 signext %a, i8 signext %b) #0 {
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%1 = icmp sgt i8 %a, %b
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br i1 %1, label %4, label %2
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; <label>:2 ; preds = %0
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%3 = mul i8 %b, %a
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br label %6
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; <label>:4 ; preds = %0
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%5 = shl i8 %b, 3
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br label %6
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; <label>:6 ; preds = %4, %2
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%.0 = phi i8 [ %3, %2 ], [ %5, %4 ]
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ret i8 %.0
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; CHECK-LABEL:foo_cmp4:
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; CHECK: if r1 s> r0
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}
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; Function Attrs: nounwind readnone uwtable
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define signext i8 @min(i8 signext %a, i8 signext %b) #0 {
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%1 = icmp slt i8 %a, %b
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%a.b = select i1 %1, i8 %a, i8 %b
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ret i8 %a.b
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; CHECK-LABEL:min:
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; CHECK: r0 = r1
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; CHECK: if r2 s> r0
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; CHECK: r0 = r2
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}
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; Function Attrs: nounwind readnone uwtable
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define zeroext i8 @minu(i8 zeroext %a, i8 zeroext %b) #0 {
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%1 = icmp ult i8 %a, 100
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%a.b = select i1 %1, i8 %a, i8 %b
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ret i8 %a.b
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; CHECK-LABEL:minu:
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; CHECK: if r{{[0-9]+}} {{<|>}} r{{[0-9]+}}
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}
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; Function Attrs: nounwind readnone uwtable
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define signext i8 @max(i8 signext %a, i8 signext %b) #0 {
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%1 = icmp sgt i8 %a, %b
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%a.b = select i1 %1, i8 %a, i8 %b
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ret i8 %a.b
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; CHECK-LABEL:max:
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; CHECK: if r0 s> r2
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}
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; Function Attrs: nounwind readnone uwtable
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define signext i8 @meq(i8 signext %a, i8 signext %b, i8 signext %c) #0 {
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%1 = icmp eq i8 %a, %b
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%c.a = select i1 %1, i8 %c, i8 %a
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ret i8 %c.a
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; CHECK-LABEL:meq:
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; CHECK: if r1 == r2
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}
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