cmd/compile: ppc64le working, not optimized enough

This time with the cherry-pick from the proper patch of
the old CL.

Stack size increased.
Corrected NaN-comparison glitches.
Marked g register as clobbered by calls.
Fixed shared libraries.

live_ssa.go still disabled because of differences.
Presumably turning on more optimization will fix
both the stack size and the live_ssa.go glitches.

Enhanced debugging output for shared libs test.

Rebased onto master.

Updates #16010.

Change-Id: I40864faf1ef32c118fb141b7ef8e854498e6b2c4
Reviewed-on: https://go-review.googlesource.com/27159
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/test/nosplit.go b/test/nosplit.go
index a58a645872..5f4e62f5b1 100644
--- a/test/nosplit.go
+++ b/test/nosplit.go
@@ -305,13 +305,13 @@ TestCases:
 				// Instead of rewriting the test cases above, adjust
 				// the first stack frame to use up the extra bytes.
 				if i == 0 {
-					size += (720 - 128) - 128
+					size += (880 - 128) - 128
 					// Noopt builds have a larger stackguard.
 					// See ../src/cmd/dist/buildruntime.go:stackGuardMultiplier
 					// This increase is included in obj.StackGuard
 					for _, s := range strings.Split(os.Getenv("GO_GCFLAGS"), " ") {
 						if s == "-N" {
-							size += 720
+							size += 880
 						}
 					}
 				}