diff --git a/src/cmd/compile/internal/ssa/gen/PPC64.rules b/src/cmd/compile/internal/ssa/gen/PPC64.rules
index 24cee6f0a3..e5d5295908 100644
--- a/src/cmd/compile/internal/ssa/gen/PPC64.rules
+++ b/src/cmd/compile/internal/ssa/gen/PPC64.rules
@@ -930,11 +930,11 @@
 (ZeroExt16to(32|64) x) -> (MOVHZreg x)
 (ZeroExt32to64 x) -> (MOVWZreg x)
 
-(Trunc(16|32|64)to8  x) && isSigned(x.Type) -> (MOVBreg x)
+(Trunc(16|32|64)to8 <t> x) && isSigned(t) -> (MOVBreg x)
 (Trunc(16|32|64)to8  x) -> (MOVBZreg x)
-(Trunc(32|64)to16 x) && isSigned(x.Type) -> (MOVHreg x)
+(Trunc(32|64)to16 <t> x) && isSigned(t) -> (MOVHreg x)
 (Trunc(32|64)to16 x) -> (MOVHZreg x)
-(Trunc64to32 x) && isSigned(x.Type) -> (MOVWreg x)
+(Trunc64to32 <t> x) && isSigned(t) -> (MOVWreg x)
 (Trunc64to32 x) -> (MOVWZreg x)
 
 (Slicemask <t> x) -> (SRADconst (NEG <t> x) [63])
diff --git a/src/cmd/compile/internal/ssa/rewritePPC64.go b/src/cmd/compile/internal/ssa/rewritePPC64.go
index d06953bafa..fdb34aec0a 100644
--- a/src/cmd/compile/internal/ssa/rewritePPC64.go
+++ b/src/cmd/compile/internal/ssa/rewritePPC64.go
@@ -30296,12 +30296,13 @@ func rewriteValuePPC64_OpTrunc_0(v *Value) bool {
 	}
 }
 func rewriteValuePPC64_OpTrunc16to8_0(v *Value) bool {
-	// match: (Trunc16to8 x)
-	// cond: isSigned(x.Type)
+	// match: (Trunc16to8 <t> x)
+	// cond: isSigned(t)
 	// result: (MOVBreg x)
 	for {
+		t := v.Type
 		x := v.Args[0]
-		if !(isSigned(x.Type)) {
+		if !(isSigned(t)) {
 			break
 		}
 		v.reset(OpPPC64MOVBreg)
@@ -30319,12 +30320,13 @@ func rewriteValuePPC64_OpTrunc16to8_0(v *Value) bool {
 	}
 }
 func rewriteValuePPC64_OpTrunc32to16_0(v *Value) bool {
-	// match: (Trunc32to16 x)
-	// cond: isSigned(x.Type)
+	// match: (Trunc32to16 <t> x)
+	// cond: isSigned(t)
 	// result: (MOVHreg x)
 	for {
+		t := v.Type
 		x := v.Args[0]
-		if !(isSigned(x.Type)) {
+		if !(isSigned(t)) {
 			break
 		}
 		v.reset(OpPPC64MOVHreg)
@@ -30342,12 +30344,13 @@ func rewriteValuePPC64_OpTrunc32to16_0(v *Value) bool {
 	}
 }
 func rewriteValuePPC64_OpTrunc32to8_0(v *Value) bool {
-	// match: (Trunc32to8 x)
-	// cond: isSigned(x.Type)
+	// match: (Trunc32to8 <t> x)
+	// cond: isSigned(t)
 	// result: (MOVBreg x)
 	for {
+		t := v.Type
 		x := v.Args[0]
-		if !(isSigned(x.Type)) {
+		if !(isSigned(t)) {
 			break
 		}
 		v.reset(OpPPC64MOVBreg)
@@ -30365,12 +30368,13 @@ func rewriteValuePPC64_OpTrunc32to8_0(v *Value) bool {
 	}
 }
 func rewriteValuePPC64_OpTrunc64to16_0(v *Value) bool {
-	// match: (Trunc64to16 x)
-	// cond: isSigned(x.Type)
+	// match: (Trunc64to16 <t> x)
+	// cond: isSigned(t)
 	// result: (MOVHreg x)
 	for {
+		t := v.Type
 		x := v.Args[0]
-		if !(isSigned(x.Type)) {
+		if !(isSigned(t)) {
 			break
 		}
 		v.reset(OpPPC64MOVHreg)
@@ -30388,12 +30392,13 @@ func rewriteValuePPC64_OpTrunc64to16_0(v *Value) bool {
 	}
 }
 func rewriteValuePPC64_OpTrunc64to32_0(v *Value) bool {
-	// match: (Trunc64to32 x)
-	// cond: isSigned(x.Type)
+	// match: (Trunc64to32 <t> x)
+	// cond: isSigned(t)
 	// result: (MOVWreg x)
 	for {
+		t := v.Type
 		x := v.Args[0]
-		if !(isSigned(x.Type)) {
+		if !(isSigned(t)) {
 			break
 		}
 		v.reset(OpPPC64MOVWreg)
@@ -30411,12 +30416,13 @@ func rewriteValuePPC64_OpTrunc64to32_0(v *Value) bool {
 	}
 }
 func rewriteValuePPC64_OpTrunc64to8_0(v *Value) bool {
-	// match: (Trunc64to8 x)
-	// cond: isSigned(x.Type)
+	// match: (Trunc64to8 <t> x)
+	// cond: isSigned(t)
 	// result: (MOVBreg x)
 	for {
+		t := v.Type
 		x := v.Args[0]
-		if !(isSigned(x.Type)) {
+		if !(isSigned(t)) {
 			break
 		}
 		v.reset(OpPPC64MOVBreg)
diff --git a/test/fixedbugs/issue29943.go b/test/fixedbugs/issue29943.go
new file mode 100644
index 0000000000..ff47de55d5
--- /dev/null
+++ b/test/fixedbugs/issue29943.go
@@ -0,0 +1,28 @@
+// run
+
+// Copyright 2019 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.
+
+// Code was miscompiled on ppc64le due to incorrect zero-extension
+// that was CSE'd.
+
+package main
+
+//go:noinline
+func g(i uint64) uint64 {
+	return uint64(uint32(i))
+}
+
+var sink uint64
+
+func main() {
+	for i := uint64(0); i < 1; i++ {
+		i32 := int32(i - 1)
+		sink = uint64((uint32(i32) << 1) ^ uint32((i32 >> 31)))
+		x := g(uint64(i32))
+		if x != uint64(uint32(i32)) {
+			panic(x)
+		}
+	}
+}