67 lines
2.3 KiB
Diff
67 lines
2.3 KiB
Diff
From 508280f7ac31c7d0ab2eaed33b26e6df59bb4dd9 Mon Sep 17 00:00:00 2001
|
|
From: "L. E. Segovia" <amy@centricular.com>
|
|
Date: Fri, 19 Jul 2024 22:25:20 -0300
|
|
Subject: [PATCH 1/2] powerpc: fix div255w which still used the inexact
|
|
substitution
|
|
|
|
The code for this architecture used the substitution suggested in the
|
|
original bug report. That one had subtle failures on armv7a and aarch64,
|
|
but I was not able to verify if they affected PowerPC too.
|
|
|
|
This commit fixes it by reusing the mulhuw instruction implementation --
|
|
sse2 can be ported directly that way.
|
|
|
|
Fixes #71
|
|
|
|
Part-of: <https://gitlab.freedesktop.org/gstreamer/orc/-/merge_requests/195>
|
|
---
|
|
orc/orcrules-altivec.c | 31 +++++++++++++++----------------
|
|
1 file changed, 15 insertions(+), 16 deletions(-)
|
|
|
|
diff --git a/orc/orcrules-altivec.c b/orc/orcrules-altivec.c
|
|
index 23409a8..a13fb5b 100644
|
|
--- a/orc/orcrules-altivec.c
|
|
+++ b/orc/orcrules-altivec.c
|
|
@@ -1513,23 +1513,22 @@ powerpc_rule_convlf (OrcCompiler *p, void *user, OrcInstruction *insn)
|
|
static void
|
|
powerpc_rule_div255w (OrcCompiler *p, void *user, OrcInstruction *insn)
|
|
{
|
|
- int src1 = ORC_SRC_ARG (p, insn, 0);
|
|
- int dest = ORC_DEST_ARG (p, insn, 0);
|
|
- int tmp = orc_compiler_get_temp_reg (p);
|
|
- int tmp2 = orc_compiler_get_temp_reg (p);
|
|
- int tmpc;
|
|
-
|
|
- tmpc = powerpc_get_constant (p, ORC_CONST_SPLAT_W, 0x0001);
|
|
-
|
|
- ORC_ASM_CODE(p," vspltish %s, 8\n", powerpc_get_regname(tmp2));
|
|
- powerpc_emit_VX(p, 0x1000034c, powerpc_regnum(tmp2), 8, 0);
|
|
-
|
|
- powerpc_emit_VX_2 (p, "vadduhm", 0x10000040, dest, src1, tmpc);
|
|
-
|
|
- powerpc_emit_VX_2 (p, "vsrh", 0x10000244, tmp, src1, tmp2);
|
|
- powerpc_emit_VX_2 (p, "vadduhm", 0x10000040, dest, dest, tmp);
|
|
+ const int src1 = ORC_SRC_ARG (p, insn, 0);
|
|
+ const int dest = ORC_DEST_ARG(p, insn, 0);
|
|
+ const int tmp = powerpc_get_constant (p, ORC_CONST_SPLAT_W, 7);
|
|
+ const int tmpc = powerpc_get_constant (p, ORC_CONST_SPLAT_W, 0x8081);
|
|
+
|
|
+ {
|
|
+ // mulhuw
|
|
+ const int perm = powerpc_get_constant_full(p, 0x10110001, 0x14150405,
|
|
+ 0x18190809, 0x1c1d0c0d);
|
|
+
|
|
+ powerpc_emit_vmuleuh (p, p->tmpreg, src1, tmpc);
|
|
+ powerpc_emit_vmulouh (p, dest, src1, tmpc);
|
|
+ powerpc_emit_vperm (p, dest, dest, p->tmpreg, perm);
|
|
+ }
|
|
|
|
- powerpc_emit_VX_2 (p, "vsrh", 0x10000244, dest, dest, tmp2);
|
|
+ powerpc_emit_VX_2 (p, "vsrh", 0x10000244, dest, dest, tmp);
|
|
}
|
|
|
|
static void
|
|
--
|
|
2.45.2
|
|
|