Thread (14 messages) 14 messages, 5 authors, 2016-06-30

[PATCHv2 3/7] ppc: bpf/jit: Optimize 64-bit Immediate loads

From: Naveen N. Rao <hidden>
Date: 2016-06-22 16:27:22
Also in: lkml, netdev
Subsystem: bpf jit for powerpc (32-bit and 64-bit), bpf [general] (safe dynamic programs and tools), linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Hari Bathini, Christophe Leroy, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds

Similar to the LI32() optimization, if the value can be represented
in 32-bits, use LI32(). Also handle loading a few specific forms of
immediate values in an optimum manner.

Cc: Matt Evans <redacted>
Cc: Denis Kirjanov <redacted>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <redacted>
Cc: Alexei Starovoitov <redacted>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ananth N Mavinakayanahalli <redacted>
Cc: Thadeu Lima de Souza Cascardo <redacted>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Naveen N. Rao <redacted>
---
 arch/powerpc/net/bpf_jit.h | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h
index a9882db..4c1e055 100644
--- a/arch/powerpc/net/bpf_jit.h
+++ b/arch/powerpc/net/bpf_jit.h
@@ -244,20 +244,25 @@ DECLARE_LOAD_FUNC(sk_load_byte_msh);
 		} } while(0)
 
 #define PPC_LI64(d, i)		do {					      \
-		if (!((uintptr_t)(i) & 0xffffffff00000000ULL))		      \
+		if ((long)(i) >= -2147483648 &&				      \
+				(long)(i) < 2147483648)			      \
 			PPC_LI32(d, i);					      \
 		else {							      \
-			PPC_LIS(d, ((uintptr_t)(i) >> 48));		      \
-			if ((uintptr_t)(i) & 0x0000ffff00000000ULL)	      \
-				PPC_ORI(d, d,				      \
-					((uintptr_t)(i) >> 32) & 0xffff);     \
+			if (!((uintptr_t)(i) & 0xffff800000000000ULL))	      \
+				PPC_LI(d, ((uintptr_t)(i) >> 32) & 0xffff);   \
+			else {						      \
+				PPC_LIS(d, ((uintptr_t)(i) >> 48));	      \
+				if ((uintptr_t)(i) & 0x0000ffff00000000ULL)   \
+					PPC_ORI(d, d,			      \
+					  ((uintptr_t)(i) >> 32) & 0xffff);   \
+			}						      \
 			PPC_SLDI(d, d, 32);				      \
 			if ((uintptr_t)(i) & 0x00000000ffff0000ULL)	      \
 				PPC_ORIS(d, d,				      \
 					 ((uintptr_t)(i) >> 16) & 0xffff);    \
 			if ((uintptr_t)(i) & 0x000000000000ffffULL)	      \
 				PPC_ORI(d, d, (uintptr_t)(i) & 0xffff);	      \
-		} } while (0);
+		} } while (0)
 
 #ifdef CONFIG_PPC64
 #define PPC_FUNC_ADDR(d,i) do { PPC_LI64(d, i); } while(0)
-- 
2.8.2
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