[U-Boot] [PATCH V2 1/2] [NEXT] arm: change relocation flag from -fPIC to -fPIE
Albert Aribaud
albert.aribaud at free.fr
Fri Sep 24 18:59:42 CEST 2010
Replace GOT indirect addressing with more efficient pic-base
relative addressing for initialized data (uninitialized data
still use GOTi indirect addressing). This also reduces code
size by 0.4% compared to -fPIC.
Signed-off-by: Albert Aribaud <albert.aribaud at free.fr>
---
SUMMARY
This patch aims at optimizing relocatable code both in size and
speed. The first patch switches from '-fPIC' to '-fPIE', which makes
initialized data accesses pc-relative rather than GOT-indirect, and
the second adds '-msingle-pic-base' which factors out GOT addressing
by computing it once and for all.
PATCHSET HISTORY
V1 Initial submission
V2 Compute RAM pic base only if actually relocating
Fixed RAM pic base computation and copy loop
arch/arm/config.mk | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index 6923f6d..138c43a 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -35,7 +35,7 @@ endif
ifndef CONFIG_SYS_ARM_WITHOUT_RELOC
# needed for relocation
-PLATFORM_RELFLAGS += -fPIC
+PLATFORM_RELFLAGS += -fPIE
endif
ifdef CONFIG_SYS_ARM_WITHOUT_RELOC
--
1.7.0.4
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