diff --git a/Source/Core/VideoCommon/GeometryShaderGen.cpp b/Source/Core/VideoCommon/GeometryShaderGen.cpp
index 10895ccf88..818a22bfa4 100644
--- a/Source/Core/VideoCommon/GeometryShaderGen.cpp
+++ b/Source/Core/VideoCommon/GeometryShaderGen.cpp
@@ -219,7 +219,11 @@ ShaderCode GenerateGeometryShaderCode(APIType api_type, const ShaderHostConfig&
   if (wireframe)
     out.Write("\tVS_OUTPUT first;\n");
 
-  out.Write("\tfor (int i = 0; i < {}; ++i) {{\n", vertex_in);
+  // Avoid D3D warning about forced unrolling of single-iteration loop
+  if (vertex_in > 1)
+    out.Write("\tfor (int i = 0; i < {}; ++i) {{\n", vertex_in);
+  else
+    out.Write("\tint i = 0;\n");
 
   if (api_type == APIType::OpenGL || api_type == APIType::Vulkan)
   {
@@ -310,7 +314,9 @@ ShaderCode GenerateGeometryShaderCode(APIType api_type, const ShaderHostConfig&
     EmitVertex(out, host_config, uid_data, "f", api_type, wireframe, stereo, true);
   }
 
-  out.Write("\t}}\n");
+  // Only close loop if previous code was in one (See D3D warning above)
+  if (vertex_in > 1)
+    out.Write("\t}}\n");
 
   EndPrimitive(out, host_config, uid_data, api_type, wireframe, stereo);
 
diff --git a/Source/Core/VideoCommon/TextureConversionShader.cpp b/Source/Core/VideoCommon/TextureConversionShader.cpp
index dd87dfe0af..ed97c48144 100644
--- a/Source/Core/VideoCommon/TextureConversionShader.cpp
+++ b/Source/Core/VideoCommon/TextureConversionShader.cpp
@@ -712,8 +712,8 @@ static void WriteXFBEncoder(ShaderCode& code, APIType api_type, const EFBCopyPar
   WriteSampleColor(code, "rgb", "color1", 1, api_type, params);
 
   // Gamma is only applied to XFB copies.
-  code.Write("  color0 = pow(color0, float3(gamma_rcp, gamma_rcp, gamma_rcp));\n"
-             "  color1 = pow(color1, float3(gamma_rcp, gamma_rcp, gamma_rcp));\n");
+  code.Write("  color0 = pow(abs(color0), float3(gamma_rcp, gamma_rcp, gamma_rcp));\n"
+             "  color1 = pow(abs(color1), float3(gamma_rcp, gamma_rcp, gamma_rcp));\n");
 
   // Convert to YUV.
   code.Write("  const float3 y_const = float3(0.257, 0.504, 0.098);\n"
diff --git a/Source/Core/VideoCommon/TextureConverterShaderGen.cpp b/Source/Core/VideoCommon/TextureConverterShaderGen.cpp
index 5b6c027c70..ae09871b98 100644
--- a/Source/Core/VideoCommon/TextureConverterShaderGen.cpp
+++ b/Source/Core/VideoCommon/TextureConverterShaderGen.cpp
@@ -278,8 +278,8 @@ ShaderCode GeneratePixelShader(APIType api_type, const UidData* uid_data)
       break;
 
     case EFBCopyFormat::XFB:
-      out.Write(
-          "  ocol0 = float4(pow(texcol.rgb, float3(gamma_rcp, gamma_rcp, gamma_rcp)), 1.0f);\n");
+      out.Write("  ocol0 = float4(pow(abs(texcol.rgb), float3(gamma_rcp, gamma_rcp, gamma_rcp)), "
+                "1.0f);\n");
       break;
 
     default:
diff --git a/Source/Core/VideoCommon/UberShaderPixel.cpp b/Source/Core/VideoCommon/UberShaderPixel.cpp
index de1aaa72f7..01df6fe5c6 100644
--- a/Source/Core/VideoCommon/UberShaderPixel.cpp
+++ b/Source/Core/VideoCommon/UberShaderPixel.cpp
@@ -827,8 +827,8 @@ ShaderCode GenPixelShader(APIType api_type, const ShaderHostConfig& host_config,
   out.Write(
       "      uint alpha_compare_op = alpha_scale << 1 | uint(alpha_op);\n"
       "\n"
-      "      int alpha_A;\n"
-      "      int alpha_B;\n"
+      "      int alpha_A = 0;\n"
+      "      int alpha_B = 0;\n"
       "      if (alpha_bias != 3u || alpha_compare_op > 5u) {{\n"
       "        // Small optimisation here: alpha_A and alpha_B are unused by compare ops 0-5\n"
       "        alpha_A = selectAlphaInput(s, ss, {0}colors_0, {0}colors_1, alpha_a) & 255;\n"