From dcd018b5c54cd23b36ef732473f0d99fbb57f6fc Mon Sep 17 00:00:00 2001
From: "Paul E. Murphy" <murp@ibm.com>
Date: Tue, 19 Sep 2023 17:01:28 -0500
Subject: cmd/internal/obj/ppc64: generate MOVD mask constants in register

Add a new form of RLDC which maps directly to the ISA definition
of rldc: RLDC Rs, $sh, $mb, Ra. This is used to generate mask
constants described below.

Using MOVD $-1, Rx; RLDC Rx, $sh, $mb, Rx, any mask constant
can be generated. A mask is a contiguous series of 1 bits, which
may wrap.

Change-Id: Ifcaae1114080ad58b5fdaa3e5fc9019e2051f282
Reviewed-on: https://go-review.googlesource.com/c/go/+/531120
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
---
 test/codegen/constants.go | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

(limited to 'test/codegen')

diff --git a/test/codegen/constants.go b/test/codegen/constants.go
index 756aeda5f7..3ce17d0ad3 100644
--- a/test/codegen/constants.go
+++ b/test/codegen/constants.go
@@ -6,6 +6,7 @@
 
 package codegen
 
+// A uint16 or sint16 constant shifted left.
 func shifted16BitConstants(out [64]uint64) {
 	// ppc64x: "MOVD\t[$]8193,", "SLD\t[$]27,"
 	out[0] = 0x0000010008000000
@@ -15,11 +16,18 @@ func shifted16BitConstants(out [64]uint64) {
 	out[2] = 0xFFFF000000000000
 	// ppc64x: "MOVD\t[$]65535", "SLD\t[$]44,"
 	out[3] = 0x0FFFF00000000000
+}
 
-	// ppc64x: "MOVD\t[$]i64.fffff00000000001[(]SB[)]"
-	out[4] = 0xFFFFF00000000001
-	// ppc64x: "MOVD\t[$]i64.fffff80000000001[(]SB[)]"
-	out[5] = 0xFFFFF80000000001
-	// ppc64x: "MOVD\t[$]i64.0ffff80000000000[(]SB[)]"
-	out[6] = 0x0FFFF80000000000
+// A contiguous set of 1 bits, potentially wrapping.
+func contiguousMaskConstants(out [64]uint64) {
+	// ppc64x: "MOVD\t[$]-1", "RLDC\tR[0-9]+, [$]44, [$]63,"
+	out[0] = 0xFFFFF00000000001
+	// ppc64x: "MOVD\t[$]-1", "RLDC\tR[0-9]+, [$]43, [$]63,"
+	out[1] = 0xFFFFF80000000001
+	// ppc64x: "MOVD\t[$]-1", "RLDC\tR[0-9]+, [$]43, [$]4,"
+	out[2] = 0x0FFFF80000000000
+	// ppc64x/power8: "MOVD\t[$]-1", "RLDC\tR[0-9]+, [$]33, [$]63,"
+	// ppc64x/power9: "MOVD\t[$]-1", "RLDC\tR[0-9]+, [$]33, [$]63,"
+	// ppc64x/power10: "MOVD\t[$]-8589934591,"
+	out[3] = 0xFFFFFFFE00000001
 }
-- 
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