ac/llvm: consolidate find lsb function.

This was the same between si and ac.

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/src/amd/common/ac_llvm_build.c b/src/amd/common/ac_llvm_build.c
index e54806a33fe2de0d97e2702bce476284e1fab3b8..ea238fa006ead716470719060aba4d890eca46da 100644 (file)
--- 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 b47d51acebbc4e69d6b6ad621ac36b0423b0577b..f7906198277362637e10330d3eb68aa817f0e18c 100644 (file)
--- 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 f78f4863a7e0247880dbf49afe326aad1ec1d475..01677558d8618ef463f43599fe1bd08f39398e8e 100644 (file)
--- 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 913b6c329597ab0f210a1fe5f80b5dc99848ac1c..a27586b3fff93fb6102f0a400c10330d5d747334 100644 (file)
--- 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. */