From 2f7848dcdaa5e90aef23b14095207c4b982120bc Mon Sep 17 00:00:00 2001
From: Hans-Kristian Arntzen <post@arntzen-software.no>
Date: Tue, 27 Aug 2019 11:19:54 +0200
Subject: [PATCH] Deal with ldexp taking uint input.

Need to value cast to int first.
---
 .../asm/frag/ldexp-uint-exponent.asm.frag     | 11 ++++++
 .../asm/frag/ldexp-uint-exponent.asm.frag     | 36 +++++++++++++++++++
 spirv_glsl.cpp                                | 22 +++++++++++-
 3 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 reference/shaders-no-opt/asm/frag/ldexp-uint-exponent.asm.frag
 create mode 100644 shaders-no-opt/asm/frag/ldexp-uint-exponent.asm.frag

diff --git a/reference/shaders-no-opt/asm/frag/ldexp-uint-exponent.asm.frag b/reference/shaders-no-opt/asm/frag/ldexp-uint-exponent.asm.frag
new file mode 100644
index 00000000..9acdd019
--- /dev/null
+++ b/reference/shaders-no-opt/asm/frag/ldexp-uint-exponent.asm.frag
@@ -0,0 +1,11 @@
+#version 310 es
+precision mediump float;
+precision highp int;
+
+layout(location = 0) out highp vec4 _GLF_color;
+
+void main()
+{
+    _GLF_color = ldexp(vec4(1.0), ivec4(uvec4(bitCount(uvec4(1u)))));
+}
+
diff --git a/shaders-no-opt/asm/frag/ldexp-uint-exponent.asm.frag b/shaders-no-opt/asm/frag/ldexp-uint-exponent.asm.frag
new file mode 100644
index 00000000..9baebc20
--- /dev/null
+++ b/shaders-no-opt/asm/frag/ldexp-uint-exponent.asm.frag
@@ -0,0 +1,36 @@
+; SPIR-V
+; Version: 1.0
+; Generator: Khronos Glslang Reference Front End; 7
+; Bound: 20
+; Schema: 0
+               OpCapability Shader
+          %1 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main" %_GLF_color
+               OpExecutionMode %main OriginUpperLeft
+               OpSource ESSL 310
+               OpName %main "main"
+               OpName %_GLF_color "_GLF_color"
+               OpDecorate %_GLF_color Location 0
+               OpDecorate %18 RelaxedPrecision
+       %void = OpTypeVoid
+          %3 = OpTypeFunction %void
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+ %_GLF_color = OpVariable %_ptr_Output_v4float Output
+    %float_1 = OpConstant %float 1
+         %11 = OpConstantComposite %v4float %float_1 %float_1 %float_1 %float_1
+       %uint = OpTypeInt 32 0
+     %v4uint = OpTypeVector %uint 4
+     %uint_1 = OpConstant %uint 1
+         %15 = OpConstantComposite %v4uint %uint_1 %uint_1 %uint_1 %uint_1
+        %int = OpTypeInt 32 1
+      %v4int = OpTypeVector %int 4
+       %main = OpFunction %void None %3
+          %5 = OpLabel
+         %18 = OpBitCount %v4uint %15
+         %19 = OpExtInst %v4float %1 Ldexp %11 %18
+               OpStore %_GLF_color %19
+               OpReturn
+               OpFunctionEnd
diff --git a/spirv_glsl.cpp b/spirv_glsl.cpp
index 51803a66..8ec8d6bb 100644
--- a/spirv_glsl.cpp
+++ b/spirv_glsl.cpp
@@ -5524,8 +5524,28 @@ void CompilerGLSL::emit_glsl_op(uint32_t result_type, uint32_t id, uint32_t eop,
 	}
 
 	case GLSLstd450Ldexp:
-		emit_binary_func_op(result_type, id, args[0], args[1], "ldexp");
+	{
+		bool forward = should_forward(args[0]) && should_forward(args[1]);
+
+		auto op0 = to_unpacked_expression(args[0]);
+		auto op1 = to_unpacked_expression(args[1]);
+		auto &op1_type = expression_type(args[1]);
+		if (op1_type.basetype != SPIRType::Int)
+		{
+			// Need a value cast here.
+			auto target_type = op1_type;
+			target_type.basetype = SPIRType::Int;
+			op1 = join(type_to_glsl_constructor(target_type), "(", op1, ")");
+		}
+
+		auto expr = join("ldexp(", op0, ", ", op1, ")");
+
+		emit_op(result_type, id, expr, forward);
+		inherit_expression_dependencies(id, args[0]);
+		inherit_expression_dependencies(id, args[1]);
 		break;
+	}
+
 	case GLSLstd450PackSnorm4x8:
 		emit_unary_func_op(result_type, id, args[0], "packSnorm4x8");
 		break;