src/cmd/compile/internal/ssa/_gen/AMD64.rules |  3 ++-
 src/cmd/compile/internal/ssa/rewriteAMD64.go  |  6 ++++--
 test/fixedbugs/issue79182.go                  | 32 ++++++++++++++++++++++++++++++++

diff --git a/src/cmd/compile/internal/ssa/_gen/AMD64.rules b/src/cmd/compile/internal/ssa/_gen/AMD64.rules
index 956077d3924011b64df9653e508920a6dcdbf7f2..f4e18337382c4007678072ee37b1bafbd462ba4b 100644
--- a/src/cmd/compile/internal/ssa/_gen/AMD64.rules
+++ b/src/cmd/compile/internal/ssa/_gen/AMD64.rules
@@ -909,7 +909,8 @@ // (x + x) << 1 -> x << 2
 (LEA(Q|L)2 [0] {s} (ADD(Q|L) x x) x) && s == nil => (SHL(Q|L)const [2] x)
 
 // (x + x) << 2 -> x << 3 and similar
-(SHL(Q|L)const [c] (ADD(Q|L) x x))  => (SHL(Q|L)const [c+1] x)
+(SHLQconst [c] (ADDQ x x)) && c < 63 => (SHLQconst [c+1] x)
+(SHLLconst [c] (ADDL x x)) && c < 31 => (SHLLconst [c+1] x)
 
 // reverse ordering of compare instruction
 (SETL (InvertFlags x)) => (SETG x)
diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64.go b/src/cmd/compile/internal/ssa/rewriteAMD64.go
index d005b15a5752640cd919512a742e076236be04d1..f32d46407533ff4a084e4d4abee05b5d7aa469bf 100644
--- a/src/cmd/compile/internal/ssa/rewriteAMD64.go
+++ b/src/cmd/compile/internal/ssa/rewriteAMD64.go
@@ -26242,6 +26242,7 @@ 		v.AddArg2(x, x)
 		return true
 	}
 	// match: (SHLLconst [c] (ADDL x x))
+	// cond: c < 31
 	// result: (SHLLconst [c+1] x)
 	for {
 		c := auxIntToInt8(v.AuxInt)
@@ -26249,7 +26250,7 @@ 		if v_0.Op != OpAMD64ADDL {
 			break
 		}
 		x := v_0.Args[1]
-		if x != v_0.Args[0] {
+		if x != v_0.Args[0] || !(c < 31) {
 			break
 		}
 		v.reset(OpAMD64SHLLconst)
@@ -26513,6 +26514,7 @@ 		v.AddArg2(x, x)
 		return true
 	}
 	// match: (SHLQconst [c] (ADDQ x x))
+	// cond: c < 63
 	// result: (SHLQconst [c+1] x)
 	for {
 		c := auxIntToInt8(v.AuxInt)
@@ -26520,7 +26522,7 @@ 		if v_0.Op != OpAMD64ADDQ {
 			break
 		}
 		x := v_0.Args[1]
-		if x != v_0.Args[0] {
+		if x != v_0.Args[0] || !(c < 63) {
 			break
 		}
 		v.reset(OpAMD64SHLQconst)
diff --git a/test/fixedbugs/issue79182.go b/test/fixedbugs/issue79182.go
new file mode 100644
index 0000000000000000000000000000000000000000..9b2694a9359cc6e2aa9dee058ee2530c0e4b9cb3
--- /dev/null
+++ b/test/fixedbugs/issue79182.go
@@ -0,0 +1,32 @@
+// run
+
+// Copyright 2026 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.
+
+// Issue 79182: SHLQconst/SHLLconst rewrite rule for (x+x)<<c
+// missed a bounds check on c, causing c+1 to overflow the valid
+// shift range and producing incorrect results on amd64.
+
+package main
+
+//go:noinline
+func shl32(x uint32) uint32 {
+	return (x + x) << 31
+}
+
+//go:noinline
+func shl64(x uint64) uint64 {
+	return (x + x) << 63
+}
+
+func main() {
+	if got := shl32(1); got != 0 {
+		println("shl32(1) =", got, "want 0")
+		panic("FAIL")
+	}
+	if got := shl64(1); got != 0 {
+		println("shl64(1) =", got, "want 0")
+		panic("FAIL")
+	}
+}