From b483ce75070d73c7413fe413e879a10796ba8cd5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niels=20M=C3=B6ller?= <nisse@lysator.liu.se>
Date: Sun, 21 Jan 2024 14:59:02 +0100
Subject: [PATCH] New macros GHASH_REDUCE.
---
powerpc64/machine.m4 | 11 +++++++++++
powerpc64/p8/ghash-update.asm | 18 +++---------------
2 files changed, 14 insertions(+), 15 deletions(-)
diff --git a/powerpc64/machine.m4 b/powerpc64/machine.m4
index 3a05e318..54d487f2 100644
--- a/powerpc64/machine.m4
+++ b/powerpc64/machine.m4
@@ -79,3 +79,14 @@ define(`OPN_XXXY',
ifelse(eval($# > 3), 1,
`OPN_XXXY($1, $2, shift(shift(shift($@))))dnl
')')
+
+C FIXME: If we allow clobber of F, no need for T register.
+C Polynomial reduction D = R + x^{-64} F mod P
+C where x^{-64} = x^{64} + P1 (mod P)
+C GHASH_REDUCE(D, R, F, P1, T)
+define(`GHASH_REDUCE', `
+ vpmsumd $5,$3,$4
+ xxswapd VSR($1),VSR($3)
+ vxor $5, $5, $2
+ vxor $1, $1, $5
+')
diff --git a/powerpc64/p8/ghash-update.asm b/powerpc64/p8/ghash-update.asm
index 6c750785..054f035d 100644
--- a/powerpc64/p8/ghash-update.asm
+++ b/powerpc64/p8/ghash-update.asm
@@ -170,11 +170,7 @@ IF_LE(`
vxor F,F,F3
vxor R,R,R3
- C reduction
- vpmsumd T,F,POLY_L
- xxswapd VSR(D),VSR(F)
- vxor R,R,T
- vxor D,R,D
+ GHASH_REDUCE(D, R, F, POLY_L, T)
addi DATA,DATA,0x40
bdnz L4x_loop
@@ -228,11 +224,7 @@ IF_LE(`
vxor F,F,F2
vxor R,R,R2
- C reduction
- vpmsumd T,F,POLY_L
- xxswapd VSR(D),VSR(F)
- vxor R,R,T
- vxor D,R,D
+ GHASH_REDUCE(D, R, F, POLY_L, T)
addi DATA,DATA,0x20
clrldi BLOCKS,BLOCKS,63 C 'set the high-order 63 bits to zeros'
@@ -261,11 +253,7 @@ IF_LE(`
vpmsumd F,H1L,C0
vpmsumd R,H1M,C0
- C reduction
- vpmsumd T,F,POLY_L
- xxswapd VSR(D),VSR(F)
- vxor R,R,T
- vxor D,R,D
+ GHASH_REDUCE(D, R, F, POLY_L, T)
addi DATA,DATA,0x10
clrldi BLOCKS,BLOCKS,60 C 'set the high-order 60 bits to zeros'
--
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