4 files changed, 97 insertions, 0 deletions
diff --git a/test/codegen/arithmetic.go b/test/codegen/arithmetic.go
index afd4d66bd9..0bdb66a376 100644
--- a/test/codegen/arithmetic.go
+++ b/test/codegen/arithmetic.go
@@ -42,6 +42,48 @@ func SubMem(arr []int, b, c, d int) int {
 	return arr[0] - arr[1]
 }
 
+func SubFromConst(a int) int {
+	// ppc64le: `SUBC\tR[0-9]+,\s[$]40,\sR`
+	// ppc64: `SUBC\tR[0-9]+,\s[$]40,\sR`
+	b := 40 - a
+	return b
+}
+
+func SubFromConstNeg(a int) int {
+	// ppc64le: `ADD\t[$]40,\sR[0-9]+,\sR`
+	// ppc64: `ADD\t[$]40,\sR[0-9]+,\sR`
+	c := 40 - (-a)
+	return c
+}
+
+func SubSubFromConst(a int) int {
+	// ppc64le: `ADD\t[$]20,\sR[0-9]+,\sR`
+	// ppc64: `ADD\t[$]20,\sR[0-9]+,\sR`
+	c := 40 - (20 - a)
+	return c
+}
+
+func AddSubFromConst(a int) int {
+	// ppc64le: `SUBC\tR[0-9]+,\s[$]60,\sR`
+	// ppc64: `SUBC\tR[0-9]+,\s[$]60,\sR`
+	c := 40 + (20 - a)
+	return c
+}
+
+func NegSubFromConst(a int) int {
+	// ppc64le: `ADD\t[$]-20,\sR[0-9]+,\sR`
+	// ppc64: `ADD\t[$]-20,\sR[0-9]+,\sR`
+	c := -(20 - a)
+	return c
+}
+
+func NegAddFromConstNeg(a int) int {
+	// ppc64le: `SUBC\tR[0-9]+,\s[$]40,\sR`
+	// ppc64: `SUBC\tR[0-9]+,\s[$]40,\sR`
+	c := -(-40 + a)
+	return c
+}
+
 // -------------------- //
 //    Multiplication    //
 // -------------------- //
diff --git a/test/codegen/mathbits.go b/test/codegen/mathbits.go
index 942605de55..4c35f26997 100644
--- a/test/codegen/mathbits.go
+++ b/test/codegen/mathbits.go
@@ -76,9 +76,17 @@ func Len64(n uint64) int {
 	// arm:"CLZ" arm64:"CLZ"
 	// mips:"CLZ"
 	// wasm:"I64Clz"
+	// ppc64le:"SUBC","CNTLZD"
+	// ppc64:"SUBC","CNTLZD"
 	return bits.Len64(n)
 }
 
+func SubFromLen64(n uint64) int {
+	// ppc64le:"CNTLZD",-"SUBC"
+	// ppc64:"CNTLZD",-"SUBC"
+	return 64 - bits.Len64(n)
+}
+
 func Len32(n uint32) int {
 	// amd64:"BSRQ","LEAQ",-"CMOVQEQ"
 	// s390x:"FLOGR"
@@ -291,6 +299,12 @@ func TrailingZeros64(n uint64) int {
 	return bits.TrailingZeros64(n)
 }
 
+func TrailingZeros64Subtract(n uint64) int {
+	// ppc64le/power8:"NEG","SUBC","ANDN","POPCNTD"
+	// ppc64le/power9:"SUBC","CNTTZD"
+	return bits.TrailingZeros64(1 - n)
+}
+
 func TrailingZeros32(n uint32) int {
 	// amd64:"BTSQ\\t\\$32","BSFQ"
 	// arm:"CLZ"
diff --git a/test/codegen/select.go b/test/codegen/select.go
new file mode 100644
index 0000000000..4426924b36
--- /dev/null
+++ b/test/codegen/select.go
@@ -0,0 +1,20 @@
+// asmcheck
+
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package codegen
+
+func f() {
+	ch1 := make(chan int)
+	ch2 := make(chan int)
+	for {
+		// amd64:-`MOVQ\t[$]0, ""..autotmp_3`
+		select {
+		case <-ch1:
+		case <-ch2:
+		default:
+		}
+	}
+}
diff --git a/test/codegen/slices.go b/test/codegen/slices.go
index 40e857f9f6..38e8a62f4b 100644
--- a/test/codegen/slices.go
+++ b/test/codegen/slices.go
@@ -347,3 +347,24 @@ func InitNotSmallSliceLiteral() []int {
 		42,
 	}
 }
+
+// --------------------------------------- //
+//   Test PPC64 SUBFCconst folding rules   //
+//   triggered by slice operations.        //
+// --------------------------------------- //
+
+func SliceWithConstCompare(a []int, b int) []int {
+	var c []int = []int{1, 2, 3, 4, 5}
+	if b+len(a) < len(c) {
+		// ppc64le:-"NEG"
+		// ppc64:-"NEG"
+		return c[b:]
+	}
+	return a
+}
+
+func SliceWithSubtractBound(a []int, b int) []int {
+	// ppc64le:"SUBC",-"NEG"
+	// ppc64:"SUBC",-"NEG"
+	return a[(3 - b):]
+}