diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index 00770547499..5e49d655fc6 100644
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -37,6 +37,7 @@
 #include "ac_binary.h"
 #include "ac_llvm_util.h"
 #include "ac_exp_param.h"
+#include "ac_shader_util.h"
 #include "si_shader_internal.h"
 #include "si_pipe.h"
 #include "sid.h"
@@ -3419,25 +3420,6 @@ struct si_ps_exports {
 	struct ac_export_args args[10];
 };
 
-unsigned si_get_spi_shader_z_format(bool writes_z, bool writes_stencil,
-				    bool writes_samplemask)
-{
-	if (writes_z) {
-		/* Z needs 32 bits. */
-		if (writes_samplemask)
-			return V_028710_SPI_SHADER_32_ABGR;
-		else if (writes_stencil)
-			return V_028710_SPI_SHADER_32_GR;
-		else
-			return V_028710_SPI_SHADER_32_R;
-	} else if (writes_stencil || writes_samplemask) {
-		/* Both stencil and sample mask need only 16 bits. */
-		return V_028710_SPI_SHADER_UINT16_ABGR;
-	} else {
-		return V_028710_SPI_SHADER_ZERO;
-	}
-}
-
 static void si_export_mrt_z(struct lp_build_tgsi_context *bld_base,
 			    LLVMValueRef depth, LLVMValueRef stencil,
 			    LLVMValueRef samplemask, struct si_ps_exports *exp)
@@ -3446,7 +3428,7 @@ static void si_export_mrt_z(struct lp_build_tgsi_context *bld_base,
 	struct lp_build_context *base = &bld_base->base;
 	struct ac_export_args args;
 	unsigned mask = 0;
-	unsigned format = si_get_spi_shader_z_format(depth != NULL,
+	unsigned format = ac_get_spi_shader_z_format(depth != NULL,
 						     stencil != NULL,
 						     samplemask != NULL);
 
diff --git a/src/gallium/drivers/radeonsi/si_shader.h b/src/gallium/drivers/radeonsi/si_shader.h
index bcb5c9da4ce..c981d3562e2 100644
--- a/src/gallium/drivers/radeonsi/si_shader.h
+++ b/src/gallium/drivers/radeonsi/si_shader.h
@@ -647,8 +647,6 @@ void si_shader_apply_scratch_relocs(struct si_shader *shader,
 void si_shader_binary_read_config(struct ac_shader_binary *binary,
 				  struct si_shader_config *conf,
 				  unsigned symbol_offset);
-unsigned si_get_spi_shader_z_format(bool writes_z, bool writes_stencil,
-				    bool writes_samplemask);
 const char *si_get_shader_name(const struct si_shader *shader, unsigned processor);
 
 /* si_shader_nir.c */
diff --git a/src/gallium/drivers/radeonsi/si_state_shaders.c b/src/gallium/drivers/radeonsi/si_state_shaders.c
index 4f683b85144..25854a1fde1 100644
--- a/src/gallium/drivers/radeonsi/si_state_shaders.c
+++ b/src/gallium/drivers/radeonsi/si_state_shaders.c
@@ -37,6 +37,7 @@
 #include "util/disk_cache.h"
 #include "util/mesa-sha1.h"
 #include "ac_exp_param.h"
+#include "ac_shader_util.h"
 
 /* SHADER_CACHE */
 
@@ -1123,7 +1124,7 @@ static void si_shader_ps(struct si_shader *shader)
 	si_pm4_set_reg(pm4, R_0286D8_SPI_PS_IN_CONTROL, spi_ps_in_control);
 
 	si_pm4_set_reg(pm4, R_028710_SPI_SHADER_Z_FORMAT,
-		       si_get_spi_shader_z_format(info->writes_z,
+		       ac_get_spi_shader_z_format(info->writes_z,
 						  info->writes_stencil,
 						  info->writes_samplemask));