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-rw-r--r--src/amd/common/ac_llvm_build.c31
-rw-r--r--src/amd/common/ac_llvm_build.h4
-rw-r--r--src/amd/common/ac_nir_to_llvm.c30
-rw-r--r--src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c27
4 files changed, 38 insertions, 54 deletions
diff --git a/src/amd/common/ac_llvm_build.c b/src/amd/common/ac_llvm_build.c
index e54806a33fe..ea238fa006e 100644
--- a/src/amd/common/ac_llvm_build.c
+++ b/src/amd/common/ac_llvm_build.c
@@ -1774,3 +1774,34 @@ void ac_lds_store(struct ac_llvm_context *ctx,
ac_build_indexed_store(ctx, ctx->lds,
dw_addr, value);
}
+
+LLVMValueRef ac_find_lsb(struct ac_llvm_context *ctx,
+ LLVMTypeRef dst_type,
+ LLVMValueRef src0)
+{
+ LLVMValueRef params[2] = {
+ src0,
+
+ /* The value of 1 means that ffs(x=0) = undef, so LLVM won't
+ * add special code to check for x=0. The reason is that
+ * the LLVM behavior for x=0 is different from what we
+ * need here. However, LLVM also assumes that ffs(x) is
+ * in [0, 31], but GLSL expects that ffs(0) = -1, so
+ * a conditional assignment to handle 0 is still required.
+ *
+ * The hardware already implements the correct behavior.
+ */
+ LLVMConstInt(ctx->i1, 1, false),
+ };
+
+ LLVMValueRef lsb = ac_build_intrinsic(ctx, "llvm.cttz.i32", ctx->i32,
+ params, 2,
+ AC_FUNC_ATTR_READNONE);
+
+ /* TODO: We need an intrinsic to skip this conditional. */
+ /* Check for zero: */
+ return LLVMBuildSelect(ctx->builder, LLVMBuildICmp(ctx->builder,
+ LLVMIntEQ, src0,
+ ctx->i32_0, ""),
+ LLVMConstInt(ctx->i32, -1, 0), lsb, "");
+}
diff --git a/src/amd/common/ac_llvm_build.h b/src/amd/common/ac_llvm_build.h
index b47d51acebb..f7906198277 100644
--- a/src/amd/common/ac_llvm_build.h
+++ b/src/amd/common/ac_llvm_build.h
@@ -297,6 +297,10 @@ LLVMValueRef ac_lds_load(struct ac_llvm_context *ctx,
LLVMValueRef dw_addr);
void ac_lds_store(struct ac_llvm_context *ctx,
LLVMValueRef dw_addr, LLVMValueRef value);
+
+LLVMValueRef ac_find_lsb(struct ac_llvm_context *ctx,
+ LLVMTypeRef dst_type,
+ LLVMValueRef src0);
#ifdef __cplusplus
}
#endif
diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index f78f4863a7e..01677558d86 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -1227,34 +1227,6 @@ static LLVMValueRef emit_bcsel(struct ac_llvm_context *ctx,
return LLVMBuildSelect(ctx->builder, v, src1, src2, "");
}
-static LLVMValueRef emit_find_lsb(struct ac_llvm_context *ctx,
- LLVMValueRef src0)
-{
- LLVMValueRef params[2] = {
- src0,
-
- /* The value of 1 means that ffs(x=0) = undef, so LLVM won't
- * add special code to check for x=0. The reason is that
- * the LLVM behavior for x=0 is different from what we
- * need here.
- *
- * The hardware already implements the correct behavior.
- */
- LLVMConstInt(ctx->i1, 1, false),
- };
-
- LLVMValueRef lsb = ac_build_intrinsic(ctx, "llvm.cttz.i32", ctx->i32,
- params, 2,
- AC_FUNC_ATTR_READNONE);
-
- /* TODO: We need an intrinsic to skip this conditional. */
- /* Check for zero: */
- return LLVMBuildSelect(ctx->builder, LLVMBuildICmp(ctx->builder,
- LLVMIntEQ, src0,
- ctx->i32_0, ""),
- LLVMConstInt(ctx->i32, -1, 0), lsb, "");
-}
-
static LLVMValueRef emit_ifind_msb(struct ac_llvm_context *ctx,
LLVMValueRef src0)
{
@@ -1895,7 +1867,7 @@ static void visit_alu(struct ac_nir_context *ctx, const nir_alu_instr *instr)
break;
case nir_op_find_lsb:
src[0] = ac_to_integer(&ctx->ac, src[0]);
- result = emit_find_lsb(&ctx->ac, src[0]);
+ result = ac_find_lsb(&ctx->ac, ctx->ac.i32, src[0]);
break;
case nir_op_ufind_msb:
src[0] = ac_to_integer(&ctx->ac, src[0]);
diff --git a/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c b/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c
index 913b6c32959..a27586b3fff 100644
--- a/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c
+++ b/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c
@@ -535,31 +535,8 @@ static void emit_lsb(const struct lp_build_tgsi_action *action,
struct lp_build_emit_data *emit_data)
{
struct si_shader_context *ctx = si_shader_context(bld_base);
- LLVMValueRef args[2] = {
- emit_data->args[0],
-
- /* The value of 1 means that ffs(x=0) = undef, so LLVM won't
- * add special code to check for x=0. The reason is that
- * the LLVM behavior for x=0 is different from what we
- * need here. However, LLVM also assumes that ffs(x) is
- * in [0, 31], but GLSL expects that ffs(0) = -1, so
- * a conditional assignment to handle 0 is still required.
- */
- LLVMConstInt(ctx->i1, 1, 0)
- };
-
- LLVMValueRef lsb =
- lp_build_intrinsic(ctx->ac.builder, "llvm.cttz.i32",
- emit_data->dst_type, args, ARRAY_SIZE(args),
- LP_FUNC_ATTR_READNONE);
-
- /* TODO: We need an intrinsic to skip this conditional. */
- /* Check for zero: */
- emit_data->output[emit_data->chan] =
- LLVMBuildSelect(ctx->ac.builder,
- LLVMBuildICmp(ctx->ac.builder, LLVMIntEQ, args[0],
- ctx->i32_0, ""),
- LLVMConstInt(ctx->i32, -1, 0), lsb, "");
+
+ emit_data->output[emit_data->chan] = ac_find_lsb(&ctx->ac, emit_data->dst_type, emit_data->args[0]);
}
/* Find the last bit set. */