From 8a1dc71b8e835b1b6b0470c1b58d2a1b9ee3bcc8 Mon Sep 17 00:00:00 2001
From: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date: Fri, 29 May 2015 15:54:28 +0200
Subject: sparc: Avoid new window for FP save/restore

Update #2270.
---
 cpukit/score/cpu/sparc/cpu_asm.S | 102 ++++++++++++++++++---------------------
 1 file changed, 48 insertions(+), 54 deletions(-)

diff --git a/cpukit/score/cpu/sparc/cpu_asm.S b/cpukit/score/cpu/sparc/cpu_asm.S
index 92674de783..ddb2a1313d 100644
--- a/cpukit/score/cpu/sparc/cpu_asm.S
+++ b/cpukit/score/cpu/sparc/cpu_asm.S
@@ -44,38 +44,35 @@
         .align 4
         PUBLIC(_CPU_Context_save_fp)
 SYM(_CPU_Context_save_fp):
-        save    %sp, -CPU_MINIMUM_STACK_FRAME_SIZE, %sp
-
         /*
          *  The following enables the floating point unit.
          */
 
-        mov     %psr, %l0
-        sethi   %hi(SPARC_PSR_EF_MASK), %l1
-        or      %l1, %lo(SPARC_PSR_EF_MASK), %l1
-        or      %l0, %l1, %l0
-        mov     %l0, %psr                  ! **** ENABLE FLOAT ACCESS ****
+        mov     %psr, %o1
+        sethi   %hi(SPARC_PSR_EF_MASK), %o2
+        or      %o2, %lo(SPARC_PSR_EF_MASK), %o2
+        or      %o1, %o2, %o1
+        mov     %o1, %psr                  ! **** ENABLE FLOAT ACCESS ****
 	nop; nop; nop;			   ! Need three nops before EF is
-        ld      [%i0], %l0		   ! active due to pipeline delay!!!
-        std     %f0, [%l0 + FO_F1_OFFSET]
-        std     %f2, [%l0 + F2_F3_OFFSET]
-        std     %f4, [%l0 + F4_F5_OFFSET]
-        std     %f6, [%l0 + F6_F7_OFFSET]
-        std     %f8, [%l0 + F8_F9_OFFSET]
-        std     %f10, [%l0 + F1O_F11_OFFSET]
-        std     %f12, [%l0 + F12_F13_OFFSET]
-        std     %f14, [%l0 + F14_F15_OFFSET]
-        std     %f16, [%l0 + F16_F17_OFFSET]
-        std     %f18, [%l0 + F18_F19_OFFSET]
-        std     %f20, [%l0 + F2O_F21_OFFSET]
-        std     %f22, [%l0 + F22_F23_OFFSET]
-        std     %f24, [%l0 + F24_F25_OFFSET]
-        std     %f26, [%l0 + F26_F27_OFFSET]
-        std     %f28, [%l0 + F28_F29_OFFSET]
-        std     %f30, [%l0 + F3O_F31_OFFSET]
-        st      %fsr, [%l0 + FSR_OFFSET]
-        ret
-        restore
+        ld      [%o0], %o1		   ! active due to pipeline delay!!!
+        std     %f0, [%o1 + FO_F1_OFFSET]
+        std     %f2, [%o1 + F2_F3_OFFSET]
+        std     %f4, [%o1 + F4_F5_OFFSET]
+        std     %f6, [%o1 + F6_F7_OFFSET]
+        std     %f8, [%o1 + F8_F9_OFFSET]
+        std     %f10, [%o1 + F1O_F11_OFFSET]
+        std     %f12, [%o1 + F12_F13_OFFSET]
+        std     %f14, [%o1 + F14_F15_OFFSET]
+        std     %f16, [%o1 + F16_F17_OFFSET]
+        std     %f18, [%o1 + F18_F19_OFFSET]
+        std     %f20, [%o1 + F2O_F21_OFFSET]
+        std     %f22, [%o1 + F22_F23_OFFSET]
+        std     %f24, [%o1 + F24_F25_OFFSET]
+        std     %f26, [%o1 + F26_F27_OFFSET]
+        std     %f28, [%o1 + F28_F29_OFFSET]
+        std     %f30, [%o1 + F3O_F31_OFFSET]
+        jmp     %o7 + 8
+         st     %fsr, [%o1 + FSR_OFFSET]
 
 /*
  *  void _CPU_Context_restore_fp(
@@ -93,38 +90,35 @@ SYM(_CPU_Context_save_fp):
         .align 4
         PUBLIC(_CPU_Context_restore_fp)
 SYM(_CPU_Context_restore_fp):
-        save    %sp, -CPU_MINIMUM_STACK_FRAME_SIZE , %sp
-
         /*
          *  The following enables the floating point unit.
          */
 
-        mov     %psr, %l0
-        sethi   %hi(SPARC_PSR_EF_MASK), %l1
-        or      %l1, %lo(SPARC_PSR_EF_MASK), %l1
-        or      %l0, %l1, %l0
-        mov     %l0, %psr                  ! **** ENABLE FLOAT ACCESS ****
+        mov     %psr, %o1
+        sethi   %hi(SPARC_PSR_EF_MASK), %o2
+        or      %o2, %lo(SPARC_PSR_EF_MASK), %o2
+        or      %o1, %o2, %o1
+        mov     %o1, %psr                  ! **** ENABLE FLOAT ACCESS ****
 	nop; nop; nop;			   ! Need three nops before EF is
-        ld      [%i0], %l0		   ! active due to pipeline delay!!!
-        ldd     [%l0 + FO_F1_OFFSET], %f0
-        ldd     [%l0 + F2_F3_OFFSET], %f2
-        ldd     [%l0 + F4_F5_OFFSET], %f4
-        ldd     [%l0 + F6_F7_OFFSET], %f6
-        ldd     [%l0 + F8_F9_OFFSET], %f8
-        ldd     [%l0 + F1O_F11_OFFSET], %f10
-        ldd     [%l0 + F12_F13_OFFSET], %f12
-        ldd     [%l0 + F14_F15_OFFSET], %f14
-        ldd     [%l0 + F16_F17_OFFSET], %f16
-        ldd     [%l0 + F18_F19_OFFSET], %f18
-        ldd     [%l0 + F2O_F21_OFFSET], %f20
-        ldd     [%l0 + F22_F23_OFFSET], %f22
-        ldd     [%l0 + F24_F25_OFFSET], %f24
-        ldd     [%l0 + F26_F27_OFFSET], %f26
-        ldd     [%l0 + F28_F29_OFFSET], %f28
-        ldd     [%l0 + F3O_F31_OFFSET], %f30
-        ld      [%l0 + FSR_OFFSET], %fsr
-        ret
-        restore
+        ld      [%o0], %o1		   ! active due to pipeline delay!!!
+        ldd     [%o1 + FO_F1_OFFSET], %f0
+        ldd     [%o1 + F2_F3_OFFSET], %f2
+        ldd     [%o1 + F4_F5_OFFSET], %f4
+        ldd     [%o1 + F6_F7_OFFSET], %f6
+        ldd     [%o1 + F8_F9_OFFSET], %f8
+        ldd     [%o1 + F1O_F11_OFFSET], %f10
+        ldd     [%o1 + F12_F13_OFFSET], %f12
+        ldd     [%o1 + F14_F15_OFFSET], %f14
+        ldd     [%o1 + F16_F17_OFFSET], %f16
+        ldd     [%o1 + F18_F19_OFFSET], %f18
+        ldd     [%o1 + F2O_F21_OFFSET], %f20
+        ldd     [%o1 + F22_F23_OFFSET], %f22
+        ldd     [%o1 + F24_F25_OFFSET], %f24
+        ldd     [%o1 + F26_F27_OFFSET], %f26
+        ldd     [%o1 + F28_F29_OFFSET], %f28
+        ldd     [%o1 + F3O_F31_OFFSET], %f30
+        jmp     %o7 + 8
+         ld     [%o1 + FSR_OFFSET], %fsr
 
 #endif /* SPARC_HAS_FPU */
 
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