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MdeModulePkg/EbcDxe AARCH64: simplify interpreter entry point thunks

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The prototypes of EbcInterpret() and ExecuteEbcImageEntryPoint() are
private to the AARCH64 implementation of EbcDxe, so we can shuffle
the arguments around a bit and make the assembler thunking glue a lot
simpler.

For ExecuteEbcImageEntryPoint(), this involves passing the EntryPoint
argument as the third parameter, rather than the first, which allows
us to do a tail call. For EbcInterpret(), instead of copying each
argument beyond #8 from one native stack frame to the next (before
another copy is made into the VM stack), pass a pointer to the
argument stack.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Feng Tian <feng.tian@intel.com>
This commit is contained in:
Ard Biesheuvel
2016-08-17 16:36:42 +02:00
parent 3226e315d2
commit 4a2aaff2fc
2 changed files with 35 additions and 82 deletions
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57
MdeModulePkg/Universal/EbcDxe/AArch64/EbcLowLevel.S
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@@ -110,50 +110,23 @@ ASM_PFX(EbcLLCALLEXNative):
//
// This function is called by the thunk code to handle an Native to EBC call
// This can handle up to 16 arguments (1-8 on in x0-x7, 9-16 are on the stack)
// x16 contains the Entry point that will be the first argument when
// x16 contains the Entry point that will be the first stacked argument when
// EBCInterpret is called.
//
//****************************************************************************
ASM_PFX(EbcLLEbcInterpret):
stp x29, x30, [sp, #-16]!
stp x29, x30, [sp, #-16]!
mov x29, sp
// copy the current arguments 9-16 from old location and add arg 7 to stack
// keeping 16 byte stack alignment
sub sp, sp, #80
str x7, [sp]
ldr x11, [sp, #96]
str x11, [sp, #8]
ldr x11, [sp, #104]
str x11, [sp, #16]
ldr x11, [sp, #112]
str x11, [sp, #24]
ldr x11, [sp, #120]
str x11, [sp, #32]
ldr x11, [sp, #128]
str x11, [sp, #40]
ldr x11, [sp, #136]
str x11, [sp, #48]
ldr x11, [sp, #144]
str x11, [sp, #56]
ldr x11, [sp, #152]
str x11, [sp, #64]
// Shift arguments and add entry point and as argument 1
mov x7, x6
mov x6, x5
mov x5, x4
mov x4, x3
mov x3, x2
mov x2, x1
mov x1, x0
mov x0, x16
// push the entry point and the address of args #9 - #16 onto the stack
add x17, sp, #16
stp x16, x17, [sp, #-16]!
// call C-code
bl ASM_PFX(EbcInterpret)
add sp, sp, #80
ldp x29, x30, [sp], #16
bl ASM_PFX(EbcInterpret)
add sp, sp, #16
ldp x29, x30, [sp], #16
ret
//****************************************************************************
@@ -165,16 +138,10 @@ ASM_PFX(EbcLLEbcInterpret):
//
//****************************************************************************
ASM_PFX(EbcLLExecuteEbcImageEntryPoint):
stp x29, x30, [sp, #-16]!
// build new parameter calling convention
mov x2, x1
mov x1, x0
mov x0, x16
mov x2, x16
// call C-code
bl ASM_PFX(ExecuteEbcImageEntryPoint)
ldp x29, x30, [sp], #16
ret
// tail call to C code
b ASM_PFX(ExecuteEbcImageEntryPoint)
//****************************************************************************
// mEbcInstructionBufferTemplate