[libclc] Enable clang fp reciprocal in clc_native_divide/recip/rsqrt/tan (#149269)

wenju-he · web-flow · commit cf36f49c042f · 2025-07-18T07:50:35.000+08:00
The pragma adds `arcp` flag to `fdiv` instruction in these functions.
The flag can provide better performance.
diff --git a/libclc/clc/lib/generic/math/clc_native_divide.inc b/libclc/clc/lib/generic/math/clc_native_divide.inc
@@ -8,5 +8,6 @@
 
 _CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_native_divide(__CLC_GENTYPE x,
                                                          __CLC_GENTYPE y) {
+  _Pragma("clang fp reciprocal(on)");
   return x / y;
 }
diff --git a/libclc/clc/lib/generic/math/clc_native_recip.inc b/libclc/clc/lib/generic/math/clc_native_recip.inc
@@ -7,5 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 _CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_native_recip(__CLC_GENTYPE val) {
+  _Pragma("clang fp reciprocal(on)");
   return 1.0f / val;
 }
diff --git a/libclc/clc/lib/generic/math/clc_native_rsqrt.inc b/libclc/clc/lib/generic/math/clc_native_rsqrt.inc
@@ -7,5 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 _CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_native_rsqrt(__CLC_GENTYPE val) {
+  _Pragma("clang fp reciprocal(on)");
   return 1.0f / __clc_native_sqrt(val);
 }
diff --git a/libclc/clc/lib/generic/math/clc_native_tan.inc b/libclc/clc/lib/generic/math/clc_native_tan.inc
@@ -7,5 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 _CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_native_tan(__CLC_GENTYPE val) {
+  _Pragma("clang fp reciprocal(on)");
   return __clc_native_sin(val) / __clc_native_cos(val);
 }

Original file line number	Diff line number	Diff line change
`@@ -8,5 +8,6 @@`
`8`	`8`
`9`	`9`	`_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_native_divide(__CLC_GENTYPE x,`
`10`	`10`	`__CLC_GENTYPE y) {`
	`11`	`+ _Pragma("clang fp reciprocal(on)");`
`11`	`12`	`return x / y;`
`12`	`13`	`}`
Original file line number	Diff line number	Diff line change
`@@ -7,5 +7,6 @@`
`7`	`7`	`//===----------------------------------------------------------------------===//`
`8`	`8`
`9`	`9`	`_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_native_recip(__CLC_GENTYPE val) {`
	`10`	`+ _Pragma("clang fp reciprocal(on)");`
`10`	`11`	`return 1.0f / val;`
`11`	`12`	`}`