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[PATCH] MIPS: Reorder operations in stackframe.h for better scheduling

To: linux-mips@linux-mips.org, ralf@linux-mips.org
Subject: [PATCH] MIPS: Reorder operations in stackframe.h for better scheduling
From: David Daney <ddaney@caviumnetworks.com>
Date: Fri, 26 Jun 2009 09:01:43 -0700
Cc: David Daney <ddaney@caviumnetworks.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
Reorder PT ops to avoid pipeline stalls.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
---
 arch/mips/include/asm/stackframe.h |   20 ++++++++++++--------
 1 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/arch/mips/include/asm/stackframe.h 
b/arch/mips/include/asm/stackframe.h
index db0fa7b..dd7e220 100644
--- a/arch/mips/include/asm/stackframe.h
+++ b/arch/mips/include/asm/stackframe.h
@@ -51,9 +51,6 @@
                LONG_S  v1, PT_ACX(sp)
 #else
                mfhi    v1
-               LONG_S  v1, PT_HI(sp)
-               mflo    v1
-               LONG_S  v1, PT_LO(sp)
 #endif
 #ifdef CONFIG_32BIT
                LONG_S  $8, PT_R8(sp)
@@ -62,10 +59,17 @@
                LONG_S  $10, PT_R10(sp)
                LONG_S  $11, PT_R11(sp)
                LONG_S  $12, PT_R12(sp)
+#ifndef CONFIG_CPU_HAS_SMARTMIPS
+               LONG_S  v1, PT_HI(sp)
+               mflo    v1
+#endif
                LONG_S  $13, PT_R13(sp)
                LONG_S  $14, PT_R14(sp)
                LONG_S  $15, PT_R15(sp)
                LONG_S  $24, PT_R24(sp)
+#ifndef CONFIG_CPU_HAS_SMARTMIPS
+               LONG_S  v1, PT_LO(sp)
+#endif
                .endm
 
                .macro  SAVE_STATIC
@@ -166,7 +170,6 @@
                LONG_S  $0, PT_R0(sp)
                mfc0    v1, CP0_STATUS
                LONG_S  $2, PT_R2(sp)
-               LONG_S  v1, PT_STATUS(sp)
 #ifdef CONFIG_MIPS_MT_SMTC
                /*
                 * Ideally, these instructions would be shuffled in
@@ -178,20 +181,21 @@
                LONG_S  v1, PT_TCSTATUS(sp)
 #endif /* CONFIG_MIPS_MT_SMTC */
                LONG_S  $4, PT_R4(sp)
-               mfc0    v1, CP0_CAUSE
                LONG_S  $5, PT_R5(sp)
-               LONG_S  v1, PT_CAUSE(sp)
+               LONG_S  v1, PT_STATUS(sp)
+               mfc0    v1, CP0_CAUSE
                LONG_S  $6, PT_R6(sp)
-               MFC0    v1, CP0_EPC
                LONG_S  $7, PT_R7(sp)
+               LONG_S  v1, PT_CAUSE(sp)
+               MFC0    v1, CP0_EPC
 #ifdef CONFIG_64BIT
                LONG_S  $8, PT_R8(sp)
                LONG_S  $9, PT_R9(sp)
 #endif
-               LONG_S  v1, PT_EPC(sp)
                LONG_S  $25, PT_R25(sp)
                LONG_S  $28, PT_R28(sp)
                LONG_S  $31, PT_R31(sp)
+               LONG_S  v1, PT_EPC(sp)
                ori     $28, sp, _THREAD_MASK
                xori    $28, _THREAD_MASK
 #ifdef CONFIG_CPU_CAVIUM_OCTEON
-- 
1.6.0.6


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