[U-Boot] [PATCH] ARM: Add comments why -msoft-float is used.

public inbox for u-boot@lists.denx.de
 help / color / mirror / Atom feed

From: Alexander Holler <holler@ahsoftware.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] ARM: Add comments why -msoft-float is used.
Date: Sun, 20 Feb 2011 04:12:12 +0100	[thread overview]
Message-ID: <1298171532-5296-1-git-send-email-holler@ahsoftware.de> (raw)

Without -msoft-float the compiler would be allowed to use certain
floating-point instructions (VFP/NEON) e.g. for optimizations, which
would require additional code, for example to save contexts for
interrupts. Add a comment which describes this in short words.

Signed-off-by: Alexander Holler <holler@ahsoftware.de>
---
 arch/arm/cpu/arm1136/config.mk           |    2 ++
 arch/arm/cpu/arm1176/config.mk           |    2 ++
 arch/arm/cpu/arm1176/s3c64xx/config.mk   |    2 ++
 arch/arm/cpu/arm720t/config.mk           |    1 +
 arch/arm/cpu/arm920t/config.mk           |    1 +
 arch/arm/cpu/arm925t/config.mk           |    1 +
 arch/arm/cpu/arm926ejs/config.mk         |    1 +
 arch/arm/cpu/arm926ejs/davinci/config.mk |    1 +
 arch/arm/cpu/arm946es/config.mk          |    1 +
 arch/arm/cpu/arm_intcm/config.mk         |    1 +
 arch/arm/cpu/armv7/config.mk             |    2 ++
 arch/arm/cpu/armv7/omap-common/config.mk |    2 ++
 arch/arm/cpu/ixp/config.mk               |    1 +
 arch/arm/cpu/lh7a40x/config.mk           |    1 +
 arch/arm/cpu/pxa/config.mk               |    1 +
 arch/arm/cpu/s3c44b0/config.mk           |    1 +
 arch/arm/cpu/sa1100/config.mk            |    1 +
 17 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/arch/arm/cpu/arm1136/config.mk b/arch/arm/cpu/arm1136/config.mk
index 3e68535..e2c32c0 100644
--- a/arch/arm/cpu/arm1136/config.mk
+++ b/arch/arm/cpu/arm1136/config.mk
@@ -20,6 +20,8 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 # MA 02111-1307 USA
 #
+
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 # Make ARMv5 to allow more compilers to work, even though its v6.
diff --git a/arch/arm/cpu/arm1176/config.mk b/arch/arm/cpu/arm1176/config.mk
index 14346cf..a9a36b4 100644
--- a/arch/arm/cpu/arm1176/config.mk
+++ b/arch/arm/cpu/arm1176/config.mk
@@ -20,6 +20,8 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 # MA 02111-1307 USA
 #
+
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 # Make ARMv5 to allow more compilers to work, even though its v6.
diff --git a/arch/arm/cpu/arm1176/s3c64xx/config.mk b/arch/arm/cpu/arm1176/s3c64xx/config.mk
index 14346cf..a9a36b4 100644
--- a/arch/arm/cpu/arm1176/s3c64xx/config.mk
+++ b/arch/arm/cpu/arm1176/s3c64xx/config.mk
@@ -20,6 +20,8 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 # MA 02111-1307 USA
 #
+
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 # Make ARMv5 to allow more compilers to work, even though its v6.
diff --git a/arch/arm/cpu/arm720t/config.mk b/arch/arm/cpu/arm720t/config.mk
index 3844c62..1d59f60 100644
--- a/arch/arm/cpu/arm720t/config.mk
+++ b/arch/arm/cpu/arm720t/config.mk
@@ -22,6 +22,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS +=  -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS += -march=armv4 -mtune=arm7tdmi
diff --git a/arch/arm/cpu/arm920t/config.mk b/arch/arm/cpu/arm920t/config.mk
index 8f6c1a3..b595088 100644
--- a/arch/arm/cpu/arm920t/config.mk
+++ b/arch/arm/cpu/arm920t/config.mk
@@ -21,6 +21,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS += -march=armv4
diff --git a/arch/arm/cpu/arm925t/config.mk b/arch/arm/cpu/arm925t/config.mk
index 8f6c1a3..b595088 100644
--- a/arch/arm/cpu/arm925t/config.mk
+++ b/arch/arm/cpu/arm925t/config.mk
@@ -21,6 +21,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS += -march=armv4
diff --git a/arch/arm/cpu/arm926ejs/config.mk b/arch/arm/cpu/arm926ejs/config.mk
index f8ef90f..fb83862 100644
--- a/arch/arm/cpu/arm926ejs/config.mk
+++ b/arch/arm/cpu/arm926ejs/config.mk
@@ -21,6 +21,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS += -march=armv5te
diff --git a/arch/arm/cpu/arm926ejs/davinci/config.mk b/arch/arm/cpu/arm926ejs/davinci/config.mk
index 565adda..081c13d 100644
--- a/arch/arm/cpu/arm926ejs/davinci/config.mk
+++ b/arch/arm/cpu/arm926ejs/davinci/config.mk
@@ -21,6 +21,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS += -march=armv5te
diff --git a/arch/arm/cpu/arm946es/config.mk b/arch/arm/cpu/arm946es/config.mk
index e783f69..f7db925 100644
--- a/arch/arm/cpu/arm946es/config.mk
+++ b/arch/arm/cpu/arm946es/config.mk
@@ -21,6 +21,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS +=  -march=armv4
diff --git a/arch/arm/cpu/arm_intcm/config.mk b/arch/arm/cpu/arm_intcm/config.mk
index e783f69..f7db925 100644
--- a/arch/arm/cpu/arm_intcm/config.mk
+++ b/arch/arm/cpu/arm_intcm/config.mk
@@ -21,6 +21,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS +=  -march=armv4
diff --git a/arch/arm/cpu/armv7/config.mk b/arch/arm/cpu/armv7/config.mk
index 49ac9c7..03ec32b 100644
--- a/arch/arm/cpu/armv7/config.mk
+++ b/arch/arm/cpu/armv7/config.mk
@@ -20,6 +20,8 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 # MA 02111-1307 USA
 #
+
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 # Make ARMv5 to allow more compilers to work, even though its v7a.
diff --git a/arch/arm/cpu/armv7/omap-common/config.mk b/arch/arm/cpu/armv7/omap-common/config.mk
index 49ac9c7..03ec32b 100644
--- a/arch/arm/cpu/armv7/omap-common/config.mk
+++ b/arch/arm/cpu/armv7/omap-common/config.mk
@@ -20,6 +20,8 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 # MA 02111-1307 USA
 #
+
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 # Make ARMv5 to allow more compilers to work, even though its v7a.
diff --git a/arch/arm/cpu/ixp/config.mk b/arch/arm/cpu/ixp/config.mk
index deca3f4..9634615 100644
--- a/arch/arm/cpu/ixp/config.mk
+++ b/arch/arm/cpu/ixp/config.mk
@@ -24,6 +24,7 @@
 
 BIG_ENDIAN = y
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float -mbig-endian
 
 PLATFORM_CPPFLAGS += -mbig-endian -march=armv5te -mtune=strongarm1100
diff --git a/arch/arm/cpu/lh7a40x/config.mk b/arch/arm/cpu/lh7a40x/config.mk
index 47b2b7b..6c4fa54 100644
--- a/arch/arm/cpu/lh7a40x/config.mk
+++ b/arch/arm/cpu/lh7a40x/config.mk
@@ -21,6 +21,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS += -march=armv4
diff --git a/arch/arm/cpu/pxa/config.mk b/arch/arm/cpu/pxa/config.mk
index a05d69c..45405d6 100644
--- a/arch/arm/cpu/pxa/config.mk
+++ b/arch/arm/cpu/pxa/config.mk
@@ -22,6 +22,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS += -march=armv5te -mtune=xscale
diff --git a/arch/arm/cpu/s3c44b0/config.mk b/arch/arm/cpu/s3c44b0/config.mk
index 7454d72..6a374a7 100644
--- a/arch/arm/cpu/s3c44b0/config.mk
+++ b/arch/arm/cpu/s3c44b0/config.mk
@@ -22,6 +22,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS += -march=armv4 -mtune=arm7tdmi -msoft-float
diff --git a/arch/arm/cpu/sa1100/config.mk b/arch/arm/cpu/sa1100/config.mk
index 6f21f41..e52e8b0 100644
--- a/arch/arm/cpu/sa1100/config.mk
+++ b/arch/arm/cpu/sa1100/config.mk
@@ -22,6 +22,7 @@
 # MA 02111-1307 USA
 #
 
+# -msoft-float forces the compiler to not use any fp-related instructions.
 PLATFORM_RELFLAGS += -fno-common -ffixed-r8 -msoft-float
 
 PLATFORM_CPPFLAGS += -march=armv4 -mtune=strongarm1100
-- 
1.7.3.4

next             reply	other threads:[~2011-02-20  3:12 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-20  3:12 Alexander Holler [this message]
2011-02-20  8:42 ` [U-Boot] [PATCH] ARM: Add comments why -msoft-float is used Wolfgang Denk
2011-02-20  9:39   ` Alexander Holler
2011-02-20  9:52     ` Alexander Holler
2011-02-20 10:05       ` Alexander Holler
2011-02-20 10:20     ` Wolfgang Denk
2011-02-20 15:43       ` Eric Cooper
2011-02-20 18:57       ` Alexander Holler

find likely ancestor, descendant, or conflicting patches for this message:
( dfblob:3e68535 dfblob:e2c32c0 dfblob:14346cf dfblob:a9a36b4
dfblob:14346cf dfblob:a9a36b4 dfblob:3844c62 dfblob:1d59f60
dfblob:8f6c1a3 dfblob:b595088 dfblob:8f6c1a3 dfblob:b595088
dfblob:f8ef90f dfblob:fb83862 dfblob:565adda dfblob:081c13d
dfblob:e783f69 dfblob:f7db925 dfblob:e783f69 dfblob:f7db925
dfblob:49ac9c7 dfblob:03ec32b dfblob:49ac9c7 dfblob:03ec32b
dfblob:deca3f4 dfblob:9634615 dfblob:47b2b7b dfblob:6c4fa54
dfblob:a05d69c dfblob:45405d6 dfblob:7454d72 dfblob:6a374a7
dfblob:6f21f41 dfblob:e52e8b0 )
 OR (
bs:"[U-Boot] [PATCH] ARM: Add comments why -msoft-float is used." )
	(help)

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1298171532-5296-1-git-send-email-holler@ahsoftware.de \
    --to=holler@ahsoftware.de \
    --cc=u-boot@lists.denx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Be sure your reply has a Subject: header at the top and a blank line before the message body.

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox