[clang] Implement the `fmod` intrinsic (PR #130320)

[Farzon Lotfi via cfe-commits]

================
@@ -22,56 +22,136 @@
 //
 // RUN: %clang_cc1 -finclude-default-header -x hlsl -triple \
 // RUN:   spirv-unknown-vulkan-compute %s -fnative-half-type \
-// RUN:   -emit-llvm -disable-llvm-passes -o - | FileCheck %s \
+// RUN:   -emit-llvm -o - | FileCheck %s \
 // RUN:   -DFNATTRS="spir_func noundef nofpclass(nan inf)" -DTYPE=half
 
 //
 // ---------- No Native Half support test -----------
 //
 // RUN: %clang_cc1 -finclude-default-header -x hlsl -triple \
-// RUN:   spirv-unknown-vulkan-compute %s -emit-llvm -disable-llvm-passes \
+// RUN:   spirv-unknown-vulkan-compute %s -emit-llvm \
 // RUN:   -o - | FileCheck %s \
 // RUN:   -DFNATTRS="spir_func noundef nofpclass(nan inf)" -DTYPE=float
 
 
 
+// DXCHECK: define [[FNATTRS]] [[TYPE]] @
+// DXCHECK: %div1.i = fdiv reassoc nnan ninf nsz arcp afn [[TYPE]] %4, %5
+// DXCHECK: %fneg.i = fneg reassoc nnan ninf nsz arcp afn [[TYPE]] %7
+// DXCHECK: %cmp.i = fcmp reassoc nnan ninf nsz arcp afn oge [[TYPE]] %6, %fneg.i
+// DXCHECK: %elt.abs.i = call reassoc nnan ninf nsz arcp afn [[TYPE]] @llvm.fabs.[[INT_TYPE]]([[TYPE]] %8)
+// DXCHECK: %hlsl.frac.i = call reassoc nnan ninf nsz arcp afn [[TYPE]] @llvm.dx.frac.[[INT_TYPE]]([[TYPE]] %elt.abs.i)
+// DXCHECK: %fneg2.i = fneg reassoc nnan ninf nsz arcp afn [[TYPE]] %11
+// DXCHECK: %hlsl.select.i = select reassoc nnan ninf nsz arcp afn i1 %loadedv.i, [[TYPE]] %10, [[TYPE]] %fneg2.i
+// DXCHECK: %mul.i = fmul reassoc nnan ninf nsz arcp afn [[TYPE]] %hlsl.select.i, %12
+// DXCHECK: ret [[TYPE]] %mul.i
----------------
farzonl wrote:

As to the `%4, %5, %6, %7` @Icohedron. I'd be fine  just wild carding them out if you are happy with that. they point to allocas and other nonsense not relevant to the fmod algorithm. If they didn't map back to the inputs in the function arguments we would have bigger problems. the type check @kmpeng is doing seems good enough to me.

https://github.com/llvm/llvm-project/pull/130320