diff options
| author | Pekka Enberg <penberg@kernel.org> | 2012-01-11 19:55:11 +0200 |
|---|---|---|
| committer | Pekka Enberg <penberg@kernel.org> | 2012-01-11 19:56:19 +0200 |
| commit | 04dc44c497bee6f589ccba7f709f1cb1be876968 (patch) | |
| tree | 7aac538044512388605b5fa596db53dd22280ede | |
| parent | 64029fed3b2288c16dafca17bd47b4b265e15533 (diff) | |
| download | jato-04dc44c497bee6f589ccba7f709f1cb1be876968.tar.gz | |
x86-32: Generate better code for static method trampolines
This patch removes a redundant push eax/pop eax pair from static method
trampolines.
Before:
[main] # Trampoline:
[main] 0xa739cab0: 55 push %ebp
[main] 0xa739cab1: 89 e5 mov %esp,%ebp
[main] 0xa739cab3: 68 40 16 b7 08 push $0x8b71640
[main] 0xa739cab8: e8 73 38 d0 60 call 0x00000000080a0330 # jit_magic_trampoline+0 (/home/penberg/src/jato/jit/trampoline.c:95)
[main]
[main] 0xa739cabd: 83 c4 04 add $0x4,%esp
[main] 0xa739cac0: 65 8b 0d f0 b7 ff ff mov %gs:0xffffb7f0,%ecx
[main] 0xa739cac7: 85 09 test %ecx,(%ecx)
[main] 0xa739cac9: 50 push %eax
[main] 0xa739caca: 58 pop %eax
[main] 0xa739cacb: 5d pop %ebp
[main] 0xa739cacc: ff e0 jmp *%eax
After:
[unknown] # Trampoline:
[unknown] 0xa7399f80: 55 push %ebp
[unknown] 0xa7399f81: 89 e5 mov %esp,%ebp
[unknown] 0xa7399f83: 68 c0 d8 c2 08 push $0x8c2d8c0
[unknown] 0xa7399f88: e8 a3 63 d0 60 call 0x00000000080a0330 # jit_magic_trampoline+0 (/home/penberg/src/jato/jit/trampoline.c:95)
[unknown]
[unknown] 0xa7399f8d: 83 c4 04 add $0x4,%esp
[unknown] 0xa7399f90: 65 8b 0d f0 b7 ff ff mov %gs:0xffffb7f0,%ecx
[unknown] 0xa7399f97: 85 09 test %ecx,(%ecx)
[unknown] 0xa7399f99: 5d pop %ebp
[unknown] 0xa7399f9a: ff e0 jmp *%eax
Signed-off-by: Pekka Enberg <penberg@kernel.org>
| -rw-r--r-- | arch/x86/emit-code.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/x86/emit-code.c b/arch/x86/emit-code.c index 345eca26..878d5819 100644 --- a/arch/x86/emit-code.c +++ b/arch/x86/emit-code.c @@ -948,18 +948,16 @@ void emit_trampoline(struct compilation_unit *cu, MACH_REG_ECX); __emit_test_membase_reg(buf, MACH_REG_ECX, 0, MACH_REG_ECX); - __emit_push_reg(buf, MACH_REG_EAX); - if (method_is_virtual(cu->method)) { + __emit_push_reg(buf, MACH_REG_EAX); __emit_push_membase(buf, MACH_REG_EBP, 0x08); __emit_push_imm(buf, (unsigned long)cu); __emit_call(buf, fixup_vtable); __emit_add_imm_reg(buf, 0x08, MACH_REG_ESP); + __emit_pop_reg(buf, MACH_REG_EAX); } - __emit_pop_reg(buf, MACH_REG_EAX); - __emit_pop_reg(buf, MACH_REG_EBP); emit_indirect_jump_reg(buf, MACH_REG_EAX); |