commit 76d0ac1a6f6f84f54d9e04e378da7823d69b3cc1
author Jason Ekstrand <jason.ekstrand@intel.com> Wed May 25 11:50:21 2016 -0700
committer Jason Ekstrand <jason.ekstrand@intel.com> Wed May 25 13:49:47 2016 -0700
tree 934fe58c36d9ed09a0331430d12401a17dd2906a
parent 0c968f9d0ef66dff741032e7bafd10d413f076fb

SPV: Don't shadow sampler parameters when performing function calls

Fixes #179

SPIRV/GlslangToSpv.cpp

diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index 950f7bd..d6ae941 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -2652,12 +2652,13 @@
     std::vector<spv::Id> rValues;
     std::vector<const glslang::TType*> argTypes;
     for (int a = 0; a < (int)glslangArgs.size(); ++a) {
+        const glslang::TType& paramType = glslangArgs[a]->getAsTyped()->getType();
         // build l-value
         builder.clearAccessChain();
         glslangArgs[a]->traverse(this);
-        argTypes.push_back(&glslangArgs[a]->getAsTyped()->getType());
-        // keep outputs as l-values, evaluate input-only as r-values
-        if (qualifiers[a] != glslang::EvqConstReadOnly) {
+        argTypes.push_back(&paramType);
+        // keep outputs as and samplers l-values, evaluate input-only as r-values
+        if (qualifiers[a] != glslang::EvqConstReadOnly || paramType.getBasicType() == glslang::EbtSampler) {
             // save l-value
             lValues.push_back(builder.getAccessChain());
         } else {
@@ -2674,10 +2675,14 @@
     int rValueCount = 0;
     std::vector<spv::Id> spvArgs;
     for (int a = 0; a < (int)glslangArgs.size(); ++a) {
+        const glslang::TType& paramType = glslangArgs[a]->getAsTyped()->getType();
         spv::Id arg;
-        if (qualifiers[a] != glslang::EvqConstReadOnly) {
+        if (paramType.getBasicType() == glslang::EbtSampler) {
+            builder.setAccessChain(lValues[lValueCount]);
+            arg = builder.accessChainGetLValue();
+            ++lValueCount;
+        } else if (qualifiers[a] != glslang::EvqConstReadOnly) {
             // need space to hold the copy
-            const glslang::TType& paramType = glslangArgs[a]->getAsTyped()->getType();
             arg = builder.createVariable(spv::StorageClassFunction, convertGlslangToSpvType(paramType), "param");
             if (qualifiers[a] == glslang::EvqIn || qualifiers[a] == glslang::EvqInOut) {
                 // need to copy the input into output space

Test/baseResults/spv.subpass.frag.out

diff --git a/Test/baseResults/spv.subpass.frag.out b/Test/baseResults/spv.subpass.frag.out
index 6393f6f..4b972ac 100644
--- a/Test/baseResults/spv.subpass.frag.out
+++ b/Test/baseResults/spv.subpass.frag.out
@@ -7,7 +7,7 @@
 
 // Module Version 10000
 // Generated by (magic number): 80001
-// Id's are bound by 70
+// Id's are bound by 68
 
                               Capability Shader
                               Capability InputAttachment
@@ -28,7 +28,6 @@
                               Name 54  "ucolor"
                               Name 57  "usub"
                               Name 62  "usubMS"
-                              Name 67  "param"
                               Decorate 30(sub) DescriptorSet 0
                               Decorate 30(sub) InputAttachmentIndex 1
                               Decorate 35(subMS) DescriptorSet 0
@@ -81,7 +80,6 @@
       62(usubMS):     61(ptr) Variable UniformConstant
          4(main):           2 Function None 3
                5:             Label
-       67(param):      8(ptr) Variable Function
               31:          28 Load 30(sub)
               32:   25(fvec4) ImageRead 31 20
                               Store 27(color) 32
@@ -106,9 +104,7 @@
               65:   52(ivec4) Load 54(ucolor)
               66:   52(ivec4) IAdd 65 64
                               Store 54(ucolor) 66
-              68:           7 Load 46(isubMS)
-                              Store 67(param) 68
-              69:           2 FunctionCall 11(foo(iIPM1;) 67(param)
+              67:           2 FunctionCall 11(foo(iIPM1;) 46(isubMS)
                               Return
                               FunctionEnd
   11(foo(iIPM1;):           2 Function None 9