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authorJoe Perches <joe@perches.com>2014-12-04 15:00:48 -0800
committerDavid S. Miller <davem@davemloft.net>2014-12-09 14:56:41 -0500
commitd148134be51fe05271ec8d47fe8c815bdee2b8e7 (patch)
tree213553d693669b3c9bbbc3b821e3680db9b33910 /arch/x86/net/bpf_jit_comp.c
parent57d743a3dec174b8f1fbf53e93ade2fea3d32bd7 (diff)
downloadop-kernel-dev-d148134be51fe05271ec8d47fe8c815bdee2b8e7.zip
op-kernel-dev-d148134be51fe05271ec8d47fe8c815bdee2b8e7.tar.gz
x86: bpf_jit_comp: Reduce is_ereg() code size
Use the (1 << reg) & mask trick to reduce code size. x86-64 size difference -O2 without profiling for various gcc versions: $ size arch/x86/net/bpf_jit_comp.o* text data bss dec hex filename 9266 4 0 9270 2436 arch/x86/net/bpf_jit_comp.o.4.4.new 10042 4 0 10046 273e arch/x86/net/bpf_jit_comp.o.4.4.old 9109 4 0 9113 2399 arch/x86/net/bpf_jit_comp.o.4.6.new 9717 4 0 9721 25f9 arch/x86/net/bpf_jit_comp.o.4.6.old 8789 4 0 8793 2259 arch/x86/net/bpf_jit_comp.o.4.7.new 10245 4 0 10249 2809 arch/x86/net/bpf_jit_comp.o.4.7.old 9671 4 0 9675 25cb arch/x86/net/bpf_jit_comp.o.4.9.new 10679 4 0 10683 29bb arch/x86/net/bpf_jit_comp.o.4.9.old Signed-off-by: Joe Perches <joe@perches.com> Tested-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/x86/net/bpf_jit_comp.c')
-rw-r--r--arch/x86/net/bpf_jit_comp.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 3f62734..09e2cea 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -135,11 +135,11 @@ static const int reg2hex[] = {
*/
static inline bool is_ereg(u32 reg)
{
- if (reg == BPF_REG_5 || reg == AUX_REG ||
- (reg >= BPF_REG_7 && reg <= BPF_REG_9))
- return true;
- else
- return false;
+ return (1 << reg) & (BIT(BPF_REG_5) |
+ BIT(AUX_REG) |
+ BIT(BPF_REG_7) |
+ BIT(BPF_REG_8) |
+ BIT(BPF_REG_9));
}
/* add modifiers if 'reg' maps to x64 registers r8..r15 */
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