From 6e5398bad16aba15db365b72cb70d1177330b603 Mon Sep 17 00:00:00 2001
From: "Paul E. Murphy" <murp@ibm.com>
Date: Fri, 16 Feb 2024 13:29:16 -0600
Subject: cmd/asm,cmd/compile: generate less instructions for most 32 bit
 constant adds on ppc64x

For GOPPC64 < 10 targets, most large 32 bit constants (those
exceeding int16 capacity) can be added using two instructions
instead of 3.

This cannot be done for values greater than 0x7FFF7FFF, so this
must be done during asm preprocessing as the optab matching
rules cannot differentiate this special case.

Likewise, constants 0x8000 <= x < 0x10000 are not converted. The
assembler currently generates 2 instructions sequences for these
constants.

Change-Id: I1ccc839c6c28fc32f15d286b2e52e2d22a2a06d4
Reviewed-on: https://go-review.googlesource.com/c/go/+/568116
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
---
 test/codegen/arithmetic.go | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

(limited to 'test')

diff --git a/test/codegen/arithmetic.go b/test/codegen/arithmetic.go
index 174c2dbcc9..dc3bab7be9 100644
--- a/test/codegen/arithmetic.go
+++ b/test/codegen/arithmetic.go
@@ -23,6 +23,32 @@ func AddLargeConst(a uint64, out []uint64) {
 	// ppc64x/power9:"MOVD\t[$]-1", "SLD\t[$]33" "ADD\tR[0-9]*"
 	// ppc64x/power8:"MOVD\t[$]-1", "SLD\t[$]33" "ADD\tR[0-9]*"
 	out[1] = a + 0xFFFFFFFE00000000
+	// ppc64x/power10:"ADD\t[$]1234567,"
+	// ppc64x/power9:"ADDIS\t[$]19,", "ADD\t[$]-10617,"
+	// ppc64x/power8:"ADDIS\t[$]19,", "ADD\t[$]-10617,"
+	out[2] = a + 1234567
+	// ppc64x/power10:"ADD\t[$]-1234567,"
+	// ppc64x/power9:"ADDIS\t[$]-19,", "ADD\t[$]10617,"
+	// ppc64x/power8:"ADDIS\t[$]-19,", "ADD\t[$]10617,"
+	out[3] = a - 1234567
+	// ppc64x/power10:"ADD\t[$]2147450879,"
+	// ppc64x/power9:"ADDIS\t[$]32767,", "ADD\t[$]32767,"
+	// ppc64x/power8:"ADDIS\t[$]32767,", "ADD\t[$]32767,"
+	out[4] = a + 0x7FFF7FFF
+	// ppc64x/power10:"ADD\t[$]-2147483647,"
+	// ppc64x/power9:"ADDIS\t[$]-32768,", "ADD\t[$]1,"
+	// ppc64x/power8:"ADDIS\t[$]-32768,", "ADD\t[$]1,"
+	out[5] = a - 2147483647
+	// ppc64x:"ADDIS\t[$]-32768,", ^"ADD\t"
+	out[6] = a - 2147483648
+	// ppc64x:"ADD\t[$]2147450880,", ^"ADDIS\t"
+	out[7] = a + 0x7FFF8000
+	// ppc64x:"ADD\t[$]-32768,", ^"ADDIS\t"
+	out[8] = a - 32768
+	// ppc64x/power10:"ADD\t[$]-32769,"
+	// ppc64x/power9:"ADDIS\t[$]-1,", "ADD\t[$]32767,"
+	// ppc64x/power8:"ADDIS\t[$]-1,", "ADD\t[$]32767,"
+	out[9] = a - 32769
 }
 
 // ----------------- //
-- 
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