cmd/compile: add floating point min/max intrinsics on s390x

Add the VECTOR FP (MINIMUM|MAXIMUM) instructions to the assembler and
use them in the compiler to implement min and max.

Note: I've allowed floating point registers to be used with the single
element instructions (those with the W instead of V prefix) to allow
easier integration into the compiler.

Change-Id: I5f80a510bd248cf483cce95f1979bf63fbae7de6
Reviewed-on: https://go-review.googlesource.com/c/go/+/684715
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Mark Freeman <mark@golang.org>
Reviewed-by: Keith Randall <khr@google.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/test/codegen/floats.go b/test/codegen/floats.go
index d04202d394..0cee497279 100644
--- a/test/codegen/floats.go
+++ b/test/codegen/floats.go
@@ -172,6 +172,7 @@ func Float64Min(a, b float64) float64 {
 	// riscv64:"FMIN"
 	// ppc64/power9:"XSMINJDP"
 	// ppc64/power10:"XSMINJDP"
+	// s390x: "WFMINDB"
 	return min(a, b)
 }
 
@@ -182,6 +183,7 @@ func Float64Max(a, b float64) float64 {
 	// riscv64:"FMAX"
 	// ppc64/power9:"XSMAXJDP"
 	// ppc64/power10:"XSMAXJDP"
+	// s390x: "WFMAXDB"
 	return max(a, b)
 }
 
@@ -192,6 +194,7 @@ func Float32Min(a, b float32) float32 {
 	// riscv64:"FMINS"
 	// ppc64/power9:"XSMINJDP"
 	// ppc64/power10:"XSMINJDP"
+	// s390x: "WFMINSB"
 	return min(a, b)
 }
 
@@ -202,6 +205,7 @@ func Float32Max(a, b float32) float32 {
 	// riscv64:"FMAXS"
 	// ppc64/power9:"XSMAXJDP"
 	// ppc64/power10:"XSMAXJDP"
+	// s390x: "WFMAXSB"
 	return max(a, b)
 }