Toggle the default option to false for pre-padding convolution flag (#21579)

If a lot of BOO shapes got regression because of pre-padding
convolutions, then set the option default to false. And only turn it on
for certain unaligned k cases. NO NEED to merge if there's no
performance regression.

Signed-off-by: yzhang93 <[email protected]>

Author: yzhang93

compiler/src/iree/compiler/Codegen/LLVMGPU/KernelConfig.cpp

@@ -129,7 +129,7 @@ static llvm::cl::opt<bool>
 llvm::cl::opt<bool> clGPUPadConvolution(
     "iree-codegen-llvmgpu-igemm-pad-convolution",
     llvm::cl::desc("enable pre-padding for convolutions in igemm path"),
-    llvm::cl::init(true));
+    llvm::cl::init(false));
 
 static llvm::cl::opt<bool>
     clUseDirectLoad("iree-llvmgpu-use-direct-load",