diff --git a/tools/drawergen/fixedfunction/drawspancodegen.cpp b/tools/drawergen/fixedfunction/drawspancodegen.cpp
index c35198ba8..2272acf8d 100644
--- a/tools/drawergen/fixedfunction/drawspancodegen.cpp
+++ b/tools/drawergen/fixedfunction/drawspancodegen.cpp
@@ -256,7 +256,7 @@ SSAVec4i DrawSpanCodegen::Shade(SSAVec4i fg, bool isSimpleShade)
 		// attenuation = 1 - MIN(dist * (1/radius), 1)
 		SSAFloat Lyz2 = light_y; // L.y*L.y + L.z*L.z
 		SSAFloat Lx = light_x - viewpos_x;
-		SSAFloat dist = SSAFloat::sqrt(Lyz2 + Lx * Lx);
+		SSAFloat dist = SSAFloat::fastsqrt(Lyz2 + Lx * Lx);
 		SSAInt attenuation = SSAInt(SSAFloat(256.0f) - SSAFloat::MIN(dist * light_rcp_radius, SSAFloat(256.0f)), true);
 		SSAVec4i contribution = (light_color * fg * attenuation) >> 16;
 
diff --git a/tools/drawergen/fixedfunction/drawwallcodegen.cpp b/tools/drawergen/fixedfunction/drawwallcodegen.cpp
index 5e7f9000d..898aebdbb 100644
--- a/tools/drawergen/fixedfunction/drawwallcodegen.cpp
+++ b/tools/drawergen/fixedfunction/drawwallcodegen.cpp
@@ -244,7 +244,7 @@ SSAVec4i DrawWallCodegen::Shade(SSAVec4i fg, int index, bool isSimpleShade)
 		// attenuation = 1 - MIN(dist * (1/radius), 1)
 		SSAFloat Lxy2 = light_x; // L.x*L.x + L.y*L.y
 		SSAFloat Lz = light_z - z;
-		SSAFloat dist = SSAFloat::sqrt(Lxy2 + Lz * Lz);
+		SSAFloat dist = SSAFloat::fastsqrt(Lxy2 + Lz * Lz);
 		SSAInt attenuation = SSAInt(SSAFloat(256.0f) - SSAFloat::MIN(dist * light_rcp_radius, SSAFloat(256.0f)), true);
 		SSAVec4i contribution = (light_color * fg * attenuation) >> 16;
 
diff --git a/tools/drawergen/ssa/ssa_float.cpp b/tools/drawergen/ssa/ssa_float.cpp
index f587d7b5a..f537792fc 100644
--- a/tools/drawergen/ssa/ssa_float.cpp
+++ b/tools/drawergen/ssa/ssa_float.cpp
@@ -25,6 +25,7 @@
 #include "ssa_int.h"
 #include "ssa_scope.h"
 #include "ssa_bool.h"
+#include "ssa_vec4f.h"
 
 SSAFloat::SSAFloat()
 : v(0)
@@ -60,6 +61,18 @@ SSAFloat SSAFloat::sqrt(SSAFloat f)
 	return SSAFloat::from_llvm(SSAScope::builder().CreateCall(SSAScope::intrinsic(llvm::Intrinsic::sqrt, params), f.v, SSAScope::hint()));
 }
 
+SSAFloat SSAFloat::fastsqrt(SSAFloat f)
+{
+	return f * rsqrt(f);
+}
+
+SSAFloat SSAFloat::rsqrt(SSAFloat f)
+{
+	llvm::Value *f_ss = SSAScope::builder().CreateInsertElement(llvm::UndefValue::get(SSAVec4f::llvm_type()), f.v, llvm::ConstantInt::get(SSAScope::context(), llvm::APInt(32, (uint64_t)0)));
+	f_ss = SSAScope::builder().CreateCall(SSAScope::intrinsic(llvm::Intrinsic::x86_sse_rsqrt_ss), f_ss, SSAScope::hint());
+	return SSAFloat::from_llvm(SSAScope::builder().CreateExtractElement(f_ss, SSAInt(0).v, SSAScope::hint()));
+}
+
 SSAFloat SSAFloat::sin(SSAFloat val)
 {
 	std::vector<llvm::Type *> params;
diff --git a/tools/drawergen/ssa/ssa_float.h b/tools/drawergen/ssa/ssa_float.h
index 69fb81a75..f7e2b93ef 100644
--- a/tools/drawergen/ssa/ssa_float.h
+++ b/tools/drawergen/ssa/ssa_float.h
@@ -37,6 +37,8 @@ public:
 	static SSAFloat from_llvm(llvm::Value *v) { return SSAFloat(v); }
 	static llvm::Type *llvm_type();
 	static SSAFloat sqrt(SSAFloat f);
+	static SSAFloat fastsqrt(SSAFloat f);
+	static SSAFloat rsqrt(SSAFloat f);
 	static SSAFloat sin(SSAFloat val);
 	static SSAFloat cos(SSAFloat val);
 	static SSAFloat pow(SSAFloat val, SSAFloat power);