[Mesa-dev] [PATCH] ac: fix 16-bit shifts

[Samuel Pitoiset]

This fixes the following LLVM error when ckeckir is set:
Type too small for ZExt

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/amd/common/ac_nir_to_llvm.c | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index 3681c07c364..925073efb85 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -671,22 +671,31 @@ static void visit_alu(struct ac_nir_context *ctx, const nir_alu_instr *instr)
 		result = LLVMBuildXor(ctx->ac.builder, src[0], src[1], "");
 		break;
 	case nir_op_ishl:
-		result = LLVMBuildShl(ctx->ac.builder, src[0],
-				      LLVMBuildZExt(ctx->ac.builder, src[1],
-						    LLVMTypeOf(src[0]), ""),
-				      "");
+		if (ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[1])) < ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[0])))
+			src[1] = LLVMBuildZExt(ctx->ac.builder, src[1],
+					       LLVMTypeOf(src[0]), "");
+		else
+			src[1] = LLVMBuildTrunc(ctx->ac.builder, src[1],
+						LLVMTypeOf(src[0]), "");
+		result = LLVMBuildShl(ctx->ac.builder, src[0], src[1], "");
 		break;
 	case nir_op_ishr:
-		result = LLVMBuildAShr(ctx->ac.builder, src[0],
-				       LLVMBuildZExt(ctx->ac.builder, src[1],
-						     LLVMTypeOf(src[0]), ""),
-				       "");
+		if (ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[1])) < ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[0])))
+			src[1] = LLVMBuildZExt(ctx->ac.builder, src[1],
+					       LLVMTypeOf(src[0]), "");
+		else
+			src[1] = LLVMBuildTrunc(ctx->ac.builder, src[1],
+						LLVMTypeOf(src[0]), "");
+		result = LLVMBuildAShr(ctx->ac.builder, src[0], src[1], "");
 		break;
 	case nir_op_ushr:
-		result = LLVMBuildLShr(ctx->ac.builder, src[0],
-				       LLVMBuildZExt(ctx->ac.builder, src[1],
-						     LLVMTypeOf(src[0]), ""),
-				       "");
+		if (ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[1])) < ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[0])))
+			src[1] = LLVMBuildZExt(ctx->ac.builder, src[1],
+					       LLVMTypeOf(src[0]), "");
+		else
+			src[1] = LLVMBuildTrunc(ctx->ac.builder, src[1],
+						LLVMTypeOf(src[0]), "");
+		result = LLVMBuildLShr(ctx->ac.builder, src[0], src[1], "");
 		break;
 	case nir_op_ilt32:
 		result = emit_int_cmp(&ctx->ac, LLVMIntSLT, src[0], src[1]);
-- 
2.21.0