/*********************************************************************/ /* Copyright 2009, 2010 The University of Texas at Austin. */ /* All rights reserved. */ /* */ /* Redistribution and use in source and binary forms, with or */ /* without modification, are permitted provided that the following */ /* conditions are met: */ /* */ /* 1. Redistributions of source code must retain the above */ /* copyright notice, this list of conditions and the following */ /* disclaimer. */ /* */ /* 2. Redistributions in binary form must reproduce the above */ /* copyright notice, this list of conditions and the following */ /* disclaimer in the documentation and/or other materials */ /* provided with the distribution. */ /* */ /* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY OF TEXAS AT */ /* AUSTIN ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, */ /* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */ /* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE */ /* DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OF TEXAS AT */ /* AUSTIN OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, */ /* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES */ /* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE */ /* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR */ /* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF */ /* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT */ /* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT */ /* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE */ /* POSSIBILITY OF SUCH DAMAGE. */ /* */ /* The views and conclusions contained in the software and */ /* documentation are those of the authors and should not be */ /* interpreted as representing official policies, either expressed */ /* or implied, of The University of Texas at Austin. */ /*********************************************************************/ #define ASSEMBLER #include "common.h" #define M ARG1 #define N ARG2 #define K ARG3 #define A ARG4 #define B ARG5 #define C ARG6 #define LDC %r10 #define I %r12 #define J %r13 #define AO %r14 #define BO %r15 #define CO %rbp #define KK %r11 #define AORIG 48(%rsp) #define STACKSIZE 64 #define ALPHA 8 + STACKSIZE(%rsp) #define OFFSET 32 + STACKSIZE(%rsp) #ifdef OPTERON #define PREFETCH prefetch #define PREFETCHW prefetchw #else #define PREFETCH prefetcht0 #define PREFETCHW prefetcht0 #endif #define PREFETCHSIZE (5 + 4 * 10) PROLOGUE PROFCODE subq $STACKSIZE, %rsp movq %rbx, 0(%rsp) movq %rbp, 8(%rsp) movq %r12, 16(%rsp) movq %r13, 24(%rsp) movq %r14, 32(%rsp) movq %r15, 40(%rsp) movq 24 + STACKSIZE(%rsp), LDC #if defined(TRMMKERNEL) && !defined(LEFT) movq OFFSET, %rax negq %rax movq %rax, KK #endif addq $8 * SIZE, A addq $8 * SIZE, B salq $BASE_SHIFT, LDC #ifdef LN movq M, %rax salq $BASE_SHIFT, %rax addq %rax, C imulq K, %rax addq %rax, A #endif #ifdef RT movq N, %rax salq $BASE_SHIFT, %rax imulq K, %rax addq %rax, B movq N, %rax imulq LDC, %rax addq %rax, C #endif #ifdef RN movq OFFSET, %rax negq %rax movq %rax, KK #endif #ifdef RT movq N, %rax subq OFFSET, %rax movq %rax, KK #endif movq N, %rax sarq $1, %rax movq %rax, J je .L30 ALIGN_4 .L01: #if defined(LT) || defined(RN) movq A, AO #else movq A, %rax movq %rax, AORIG #endif #ifdef RT movq K, %rax salq $1 + BASE_SHIFT, %rax subq %rax, B #endif lea (, LDC, 2), %rax #ifdef RT subq %rax, C #endif movq C, CO #ifndef RT addq %rax, C #endif #ifdef LN movq OFFSET, %rax addq M, %rax movq %rax, KK #endif #ifdef LT movq OFFSET, %rax movq %rax, KK #endif movq M, I sarq $1, I je .L20 ALIGN_4 .L11: #ifdef LN movq K, %rax salq $1 + BASE_SHIFT, %rax subq %rax, AORIG #endif #if defined(LN) || defined(RT) movq KK, %rax salq $BASE_SHIFT, %rax movq AORIG, AO leaq (AO, %rax, 2), AO leaq (B, %rax, 2), BO #else movq B, BO #endif fldz fldz fldz fldz #if defined(HAVE_3DNOW) prefetchw 2 * SIZE(CO) prefetchw 2 * SIZE(CO, LDC, 1) #elif defined(HAVE_SSE) prefetchnta 2 * SIZE(CO) prefetchnta 2 * SIZE(CO, LDC, 1) #endif #if defined(LT) || defined(RN) movq KK, %rax #else movq K, %rax subq KK, %rax #endif sarq $2, %rax je .L15 ALIGN_4 .L12: PREFETCH (PREFETCHSIZE + 0) * SIZE(AO) FLD -8 * SIZE(AO) FLD -8 * SIZE(BO) fld %st(1) fmul %st(1), %st faddp %st, %st(3) FLD -7 * SIZE(BO) fmul %st, %st(2) FLD -7 * SIZE(AO) fmul %st, %st(2) fmulp %st, %st(1) faddp %st, %st(6) faddp %st, %st(4) faddp %st, %st(2) FLD -6 * SIZE(AO) FLD -6 * SIZE(BO) fld %st(1) fmul %st(1), %st faddp %st, %st(3) FLD -5 * SIZE(BO) fmul %st, %st(2) FLD -5 * SIZE(AO) fmul %st, %st(2) fmulp %st, %st(1) faddp %st, %st(6) faddp %st, %st(4) faddp %st, %st(2) PREFETCH (PREFETCHSIZE + 4) * SIZE(AO) FLD -4 * SIZE(AO) FLD -4 * SIZE(BO) fld %st(1) fmul %st(1), %st faddp %st, %st(3) FLD -3 * SIZE(BO) fmul %st, %st(2) FLD -3 * SIZE(AO) fmul %st, %st(2) fmulp %st, %st(1) faddp %st, %st(6) faddp %st, %st(4) faddp %st, %st(2) FLD -2 * SIZE(AO) FLD -2 * SIZE(BO) fld %st(1) fmul %st(1), %st faddp %st, %st(3) FLD -1 * SIZE(BO) fmul %st, %st(2) FLD -1 * SIZE(AO) fmul %st, %st(2) fmulp %st, %st(1) faddp %st, %st(6) faddp %st, %st(4) faddp %st, %st(2) addq $8 * SIZE,AO addq $8 * SIZE,BO decq %rax jne .L12 ALIGN_4 .L15: #if defined(LT) || defined(RN) movq KK, %rax #else movq K, %rax subq KK, %rax #endif and $3, %rax je .L18 ALIGN_4 .L16: FLD -8 * SIZE(AO) FLD -8 * SIZE(BO) fld %st(1) fmul %st(1), %st faddp %st, %st(3) FLD -7 * SIZE(BO) fmul %st, %st(2) FLD -7 * SIZE(AO) fmul %st, %st(2) fmulp %st, %st(1) faddp %st, %st(6) faddp %st, %st(4) faddp %st, %st(2) addq $2 * SIZE,AO addq $2 * SIZE,BO decq %rax jne .L16 ALIGN_4 .L18: #if defined(LN) || defined(RT) movq KK, %rax #ifdef LN subq $2, %rax #else subq $2, %rax #endif salq $BASE_SHIFT, %rax movq AORIG, AO leaq (AO, %rax, 2), AO leaq (B, %rax, 2), BO #endif #if defined(LN) || defined(LT) FLD -8 * SIZE(BO) fsubp %st, %st(1) FLD -7 * SIZE(BO) fsubp %st, %st(2) FLD -6 * SIZE(BO) fsubp %st, %st(3) FLD -5 * SIZE(BO) fsubp %st, %st(4) #else FLD -8 * SIZE(AO) fsubp %st, %st(1) FLD -7 * SIZE(AO) fsubp %st, %st(3) FLD -6 * SIZE(AO) fsubp %st, %st(2) FLD -5 * SIZE(AO) fsubp %st, %st(4) #endif #ifdef LN FLD -5 * SIZE(AO) fmul %st, %st(3) fmulp %st, %st(4) FLD -6 * SIZE(AO) fmul %st(3), %st FLD -6 * SIZE(AO) fmul %st(5), %st fsubrp %st, %st(3) fsubrp %st, %st(1) FLD -8 * SIZE(AO) fmul %st, %st(1) fmulp %st, %st(2) #endif #ifdef LT FLD -8 * SIZE(AO) fmul %st, %st(1) fmulp %st, %st(2) FLD -7 * SIZE(AO) fmul %st(1), %st FLD -7 * SIZE(AO) fmul %st(3), %st fsubrp %st, %st(5) fsubrp %st, %st(3) FLD -5 * SIZE(AO) fmul %st, %st(3) fmulp %st, %st(4) #endif #ifdef RN FLD -8 * SIZE(BO) fmul %st, %st(1) fmulp %st, %st(3) FLD -7 * SIZE(BO) fmul %st(1), %st FLD -7 * SIZE(BO) fmul %st(4), %st fsubrp %st, %st(5) fsubrp %st, %st(2) FLD -5 * SIZE(BO) fmul %st, %st(2) fmulp %st, %st(4) #endif #ifdef RT FLD -5 * SIZE(BO) fmul %st, %st(2) fmulp %st, %st(4) FLD -6 * SIZE(BO) fmul %st(2), %st FLD -6 * SIZE(BO) fmul %st(5), %st fsubrp %st, %st(4) fsubrp %st, %st(1) FLD -8 * SIZE(BO) fmul %st, %st(1) fmulp %st, %st(3) #endif #ifdef LN subq $2 * SIZE, CO #endif #if defined(LN) || defined(LT) fld %st FST -8 * SIZE(BO) fxch %st(1) fld %st FST -7 * SIZE(BO) fxch %st(2) fld %st FST -6 * SIZE(BO) fxch %st(3) fld %st FST -5 * SIZE(BO) FST 1 * SIZE(CO, LDC) FST 0 * SIZE(CO) FST 0 * SIZE(CO, LDC) FST 1 * SIZE(CO) #else fld %st FST -8 * SIZE(AO) fxch %st(2) fld %st FST -7 * SIZE(AO) fxch %st(1) fld %st FST -6 * SIZE(AO) fxch %st(3) fld %st FST -5 * SIZE(AO) FST 1 * SIZE(CO, LDC) FST 1 * SIZE(CO) FST 0 * SIZE(CO) FST 0 * SIZE(CO, LDC) #endif #ifndef LN addq $2 * SIZE, CO #endif #if defined(LT) || defined(RN) movq K, %rax subq KK, %rax salq $BASE_SHIFT, %rax leaq (AO, %rax, 2), AO leaq (BO, %rax, 2), BO #endif #ifdef LN subq $2, KK #endif #ifdef LT addq $2, KK #endif #ifdef RT movq K, %rax salq $1 + BASE_SHIFT, %rax addq %rax, AORIG #endif decq I jne .L11 ALIGN_4 .L20: movq M, %rax andq $1, %rax je .L29 ALIGN_4 .L21: #ifdef LN movq K, %rax salq $0 + BASE_SHIFT, %rax subq %rax, AORIG #endif #if defined(LN) || defined(RT) movq KK, %rax salq $BASE_SHIFT, %rax movq AORIG, AO leaq (AO, %rax, 1), AO leaq (B, %rax, 2), BO #else movq B, BO #endif fldz fldz #if defined(LT) || defined(RN) movq KK, %rax #else movq K, %rax subq KK, %rax #endif sarq $2, %rax je .L25 ALIGN_4 .L22: PREFETCH (PREFETCHSIZE + 0) * SIZE(AO) FLD -8 * SIZE(AO) FLD -8 * SIZE(BO) fmul %st(1), %st faddp %st, %st(2) FLD -7 * SIZE(BO) fmulp %st, %st(1) faddp %st, %st(2) FLD -7 * SIZE(AO) FLD -6 * SIZE(BO) fmul %st(1), %st faddp %st, %st(2) FLD -5 * SIZE(BO) fmulp %st, %st(1) faddp %st, %st(2) FLD -6 * SIZE(AO) FLD -4 * SIZE(BO) fmul %st(1), %st faddp %st, %st(2) FLD -3 * SIZE(BO) fmulp %st, %st(1) faddp %st, %st(2) FLD -5 * SIZE(AO) FLD -2 * SIZE(BO) fmul %st(1), %st faddp %st, %st(2) FLD -1 * SIZE(BO) fmulp %st, %st(1) faddp %st, %st(2) addq $4 * SIZE,AO addq $8 * SIZE,BO decq %rax jne .L22 ALIGN_4 .L25: #if defined(LT) || defined(RN) movq KK, %rax #else movq K, %rax subq KK, %rax #endif and $3, %rax je .L28 ALIGN_4 .L26: FLD -8 * SIZE(AO) FLD -8 * SIZE(BO) fmul %st(1), %st faddp %st, %st(2) FLD -7 * SIZE(BO) fmulp %st, %st(1) faddp %st, %st(2) addq $1 * SIZE,AO addq $2 * SIZE,BO decq %rax jne .L26 ALIGN_4 .L28: #if defined(LN) || defined(RT) movq KK, %rax #ifdef LN subq $1, %rax #else subq $2, %rax #endif salq $BASE_SHIFT, %rax movq AORIG, AO leaq (AO, %rax, 1), AO leaq (B, %rax, 2), BO #endif #if defined(LN) || defined(LT) FLD -8 * SIZE(BO) fsubp %st, %st(1) FLD -7 * SIZE(BO) fsubp %st, %st(2) #else FLD -8 * SIZE(AO) fsubp %st, %st(1) FLD -7 * SIZE(AO) fsubp %st, %st(2) #endif #if defined(LN) || defined(LT) FLD -8 * SIZE(AO) fmul %st, %st(1) fmulp %st, %st(2) #endif #ifdef RN FLD -8 * SIZE(BO) fmulp %st, %st(1) FLD -7 * SIZE(BO) fmul %st(1), %st fsubrp %st, %st(2) FLD -5 * SIZE(BO) fmulp %st, %st(2) #endif #ifdef RT FLD -5 * SIZE(BO) fmulp %st, %st(2) FLD -6 * SIZE(BO) fmul %st(2), %st fsubrp %st, %st(1) FLD -8 * SIZE(BO) fmulp %st, %st(1) #endif #ifdef LN subq $1 * SIZE, CO #endif #if defined(LN) || defined(LT) fld %st FST -8 * SIZE(BO) fxch %st(1) fld %st FST -7 * SIZE(BO) #else fld %st FST -8 * SIZE(AO) fxch %st(1) fld %st FST -7 * SIZE(AO) #endif FST 0 * SIZE(CO, LDC) FST 0 * SIZE(CO) #ifndef LN addq $1 * SIZE, CO #endif #if defined(LT) || defined(RN) movq K, %rax subq KK, %rax salq $BASE_SHIFT, %rax leaq (AO, %rax, 1), AO leaq (BO, %rax, 2), BO #endif #ifdef LN subq $1, KK #endif #ifdef LT addq $1, KK #endif #ifdef RT movq K, %rax salq $0 + BASE_SHIFT, %rax addq %rax, AORIG #endif ALIGN_4 .L29: #ifdef LN movq K, %rax salq $BASE_SHIFT, %rax leaq (B, %rax, 2), B #endif #if defined(LT) || defined(RN) movq BO, B #endif #ifdef RN addq $2, KK #endif #ifdef RT subq $2, KK #endif decq J jne .L01 ALIGN_4 .L30: movq N, %rax testq $1, %rax je .L999 #if defined(LT) || defined(RN) movq A, AO #else movq A, %rax movq %rax, AORIG #endif #ifdef RT movq K, %rax salq $0 + BASE_SHIFT, %rax subq %rax, B #endif #ifdef RT subq LDC, C #endif movq C, CO #ifndef RT addq LDC, C #endif #ifdef LN movq OFFSET, %rax addq M, %rax movq %rax, KK #endif #ifdef LT movq OFFSET, %rax movq %rax, KK #endif movq M, I sarq $1, I je .L40 ALIGN_4 .L31: #ifdef LN movq K, %rax salq $1 + BASE_SHIFT, %rax subq %rax, AORIG #endif #if defined(LN) || defined(RT) movq KK, %rax salq $BASE_SHIFT, %rax movq AORIG, AO leaq (AO, %rax, 2), AO leaq (B, %rax, 1), BO #else movq B, BO #endif fldz fldz #if defined(HAVE_3DNOW) prefetchw 2 * SIZE(CO) #elif defined(HAVE_SSE) prefetchnta 2 * SIZE(CO) #endif #if defined(LT) || defined(RN) movq KK, %rax #else movq K, %rax subq KK, %rax #endif sarq $2, %rax je .L35 ALIGN_4 .L32: PREFETCH (PREFETCHSIZE + 0) * SIZE(AO) FLD -8 * SIZE(BO) FLD -8 * SIZE(AO) fmul %st(1), %st faddp %st, %st(2) FLD -7 * SIZE(AO) fmulp %st, %st(1) faddp %st, %st(2) FLD -7 * SIZE(BO) FLD -6 * SIZE(AO) fmul %st(1), %st faddp %st, %st(2) FLD -5 * SIZE(AO) fmulp %st, %st(1) faddp %st, %st(2) FLD -6 * SIZE(BO) FLD -4 * SIZE(AO) fmul %st(1), %st faddp %st, %st(2) FLD -3 * SIZE(AO) fmulp %st, %st(1) faddp %st, %st(2) FLD -5 * SIZE(BO) FLD -2 * SIZE(AO) fmul %st(1), %st faddp %st, %st(2) FLD -1 * SIZE(AO) fmulp %st, %st(1) faddp %st, %st(2) addq $8 * SIZE,AO addq $4 * SIZE,BO decq %rax jne .L32 ALIGN_4 .L35: #if defined(LT) || defined(RN) movq KK, %rax #else movq K, %rax subq KK, %rax #endif and $3, %rax je .L38 ALIGN_4 .L36: FLD -8 * SIZE(BO) FLD -8 * SIZE(AO) fmul %st(1), %st faddp %st, %st(2) FLD -7 * SIZE(AO) fmulp %st, %st(1) faddp %st, %st(2) addq $2 * SIZE,AO addq $1 * SIZE,BO decq %rax jne .L36 ALIGN_4 .L38: #if defined(LN) || defined(RT) movq KK, %rax #ifdef LN subq $2, %rax #else subq $1, %rax #endif salq $BASE_SHIFT, %rax movq AORIG, AO leaq (AO, %rax, 2), AO leaq (B, %rax, 1), BO #endif #if defined(LN) || defined(LT) FLD -8 * SIZE(BO) fsubp %st, %st(1) FLD -7 * SIZE(BO) fsubp %st, %st(2) #else FLD -8 * SIZE(AO) fsubp %st, %st(1) FLD -7 * SIZE(AO) fsubp %st, %st(2) #endif #ifdef LN FLD -5 * SIZE(AO) fmulp %st, %st(2) FLD -6 * SIZE(AO) fmul %st(2), %st fsubrp %st, %st(1) FLD -8 * SIZE(AO) fmulp %st, %st(1) #endif #ifdef LT FLD -8 * SIZE(AO) fmulp %st, %st(1) FLD -7 * SIZE(AO) fmul %st(1), %st fsubrp %st, %st(2) FLD -5 * SIZE(AO) fmulp %st, %st(2) #endif #ifdef RN FLD -8 * SIZE(BO) fmul %st, %st(1) fmulp %st, %st(2) #endif #ifdef RT FLD -8 * SIZE(BO) fmul %st, %st(1) fmulp %st, %st(2) #endif #ifdef LN subq $2 * SIZE, CO #endif #if defined(LN) || defined(LT) fld %st FST -8 * SIZE(BO) fxch %st(1) fld %st FST -7 * SIZE(BO) #else fld %st FST -8 * SIZE(AO) fxch %st(1) fld %st FST -7 * SIZE(AO) #endif FST 1 * SIZE(CO) FST 0 * SIZE(CO) #ifndef LN addq $2 * SIZE, CO #endif #if defined(LT) || defined(RN) movq K, %rax subq KK, %rax salq $BASE_SHIFT, %rax leaq (AO, %rax, 2), AO leaq (BO, %rax, 1), BO #endif #ifdef LN subq $2, KK #endif #ifdef LT addq $2, KK #endif #ifdef RT movq K, %rax salq $1 + BASE_SHIFT, %rax addq %rax, AORIG #endif decq I jne .L31 ALIGN_4 .L40: movq M, %rax andq $1, %rax je .L49 ALIGN_4 .L41: #ifdef LN movq K, %rax salq $0 + BASE_SHIFT, %rax subq %rax, AORIG #endif #if defined(LN) || defined(RT) movq KK, %rax salq $BASE_SHIFT, %rax movq AORIG, AO leaq (AO, %rax, 1), AO leaq (B, %rax, 1), BO #else movq B, BO #endif fldz #if defined(LT) || defined(RN) movq KK, %rax #else movq K, %rax subq KK, %rax #endif sarq $2, %rax je .L45 ALIGN_4 .L42: PREFETCH (PREFETCHSIZE + 0) * SIZE(AO) FLD -8 * SIZE(AO) FLD -8 * SIZE(BO) fmulp %st, %st(1) faddp %st, %st(1) FLD -7 * SIZE(AO) FLD -7 * SIZE(BO) fmulp %st, %st(1) faddp %st, %st(1) FLD -6 * SIZE(AO) FLD -6 * SIZE(BO) fmulp %st, %st(1) faddp %st, %st(1) FLD -5 * SIZE(AO) FLD -5 * SIZE(BO) fmulp %st, %st(1) faddp %st, %st(1) addq $4 * SIZE,AO addq $4 * SIZE,BO decq %rax jne .L42 ALIGN_4 .L45: #if defined(LT) || defined(RN) movq KK, %rax #else movq K, %rax subq KK, %rax #endif and $3, %rax je .L48 ALIGN_4 .L46: FLD -8 * SIZE(AO) FLD -8 * SIZE(BO) fmulp %st, %st(1) faddp %st, %st(1) addq $1 * SIZE,AO addq $1 * SIZE,BO decq %rax jne .L46 ALIGN_4 .L48: #if defined(LN) || defined(RT) movq KK, %rax #ifdef LN subq $1, %rax #else subq $1, %rax #endif salq $BASE_SHIFT, %rax movq AORIG, AO leaq (AO, %rax, 1), AO leaq (B, %rax, 1), BO #endif #if defined(LN) || defined(LT) FLD -8 * SIZE(BO) fsubp %st, %st(1) #else FLD -8 * SIZE(AO) fsubp %st, %st(1) #endif #ifdef LN FLD -8 * SIZE(AO) fmulp %st, %st(1) #endif #ifdef LT FLD -8 * SIZE(AO) fmulp %st, %st(1) #endif #ifdef RN FLD -8 * SIZE(BO) fmulp %st, %st(1) #endif #ifdef RT FLD -8 * SIZE(BO) fmulp %st, %st(1) #endif #ifdef LN subq $1 * SIZE, CO #endif #if defined(LN) || defined(LT) fld %st FST -8 * SIZE(BO) #else fld %st FST -8 * SIZE(AO) #endif FST 0 * SIZE(CO) #ifndef LN addq $1 * SIZE, CO #endif #if defined(LT) || defined(RN) movq K, %rax subq KK, %rax salq $BASE_SHIFT, %rax leaq (AO, %rax, 1), AO leaq (BO, %rax, 1), BO #endif #ifdef LN subq $1, KK #endif #ifdef LT addq $1, KK #endif #ifdef RT movq K, %rax salq $0 + BASE_SHIFT, %rax addq %rax, AORIG #endif ALIGN_4 .L49: #ifdef LN movq K, %rax salq $BASE_SHIFT, %rax leaq (B, %rax, 1), B #endif #if defined(LT) || defined(RN) movq BO, B #endif #ifdef RN addq $1, KK #endif #ifdef RT subq $1, KK #endif ALIGN_4 .L999: movq 0(%rsp), %rbx movq 8(%rsp), %rbp movq 16(%rsp), %r12 movq 24(%rsp), %r13 movq 32(%rsp), %r14 movq 40(%rsp), %r15 addq $STACKSIZE, %rsp ret EPILOGUE