Mesa (master): gallivm: Altivec vector add/sub intrisics

[Jose Fonseca]

Module: Mesa
Branch: master
Commit: dd5c58081672bd495e0ffef1c3cc1229620f0f88
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=dd5c58081672bd495e0ffef1c3cc1229620f0f88

Author: Adhemerval Zanella <azanella at linux.vnet.ibm.com>
Date:   Thu Nov 22 11:20:42 2012 -0600

gallivm: Altivec vector add/sub intrisics

This patch add correct vector addition and substraction intrisics when
using Altivec with PPC. Current code uses default path and LLVM backend
ends up issuing carry-out arithmetic instruction while it is expected
saturated ones.

It also includes a fix for PowerPC where char are unsigned by default,
resulting in bogus values for vector shifting.

Reviewed-by: Roland Scheidegger <sroland at vmware.com>
Reviewed-by: Jose Fonseca <jfonseca at vmware.com>

---

 src/gallium/auxiliary/gallivm/lp_bld_arit.c    |   40 +++++++++++++++--------
 src/gallium/auxiliary/gallivm/lp_bld_swizzle.c |    2 +-
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
index a4d7d98..c3df3bf 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
@@ -365,13 +365,19 @@ lp_build_add(struct lp_build_context *bld,
       if(a == bld->one || b == bld->one)
         return bld->one;
 
-      if(util_cpu_caps.has_sse2 &&
-         type.width * type.length == 128 &&
-         !type.floating && !type.fixed) {
-         if(type.width == 8)
-            intrinsic = type.sign ? "llvm.x86.sse2.padds.b" : "llvm.x86.sse2.paddus.b";
-         if(type.width == 16)
-            intrinsic = type.sign ? "llvm.x86.sse2.padds.w" : "llvm.x86.sse2.paddus.w";
+      if (type.width * type.length == 128 &&
+          !type.floating && !type.fixed) {
+         if(util_cpu_caps.has_sse2) {
+           if(type.width == 8)
+             intrinsic = type.sign ? "llvm.x86.sse2.padds.b" : "llvm.x86.sse2.paddus.b";
+           if(type.width == 16)
+             intrinsic = type.sign ? "llvm.x86.sse2.padds.w" : "llvm.x86.sse2.paddus.w";
+         } else if (util_cpu_caps.has_altivec) {
+           if(type.width == 8)
+              intrinsic = type.sign ? "llvm.ppc.altivec.vaddsbs" : "llvm.ppc.altivec.vaddubs";
+           if(type.width == 16)
+              intrinsic = type.sign ? "llvm.ppc.altivec.vaddsws" : "llvm.ppc.altivec.vadduws";
+         }
       }
    
       if(intrinsic)
@@ -636,13 +642,19 @@ lp_build_sub(struct lp_build_context *bld,
       if(b == bld->one)
         return bld->zero;
 
-      if(util_cpu_caps.has_sse2 &&
-         type.width * type.length == 128 &&
-         !type.floating && !type.fixed) {
-         if(type.width == 8)
-            intrinsic = type.sign ? "llvm.x86.sse2.psubs.b" : "llvm.x86.sse2.psubus.b";
-         if(type.width == 16)
-            intrinsic = type.sign ? "llvm.x86.sse2.psubs.w" : "llvm.x86.sse2.psubus.w";
+      if (type.width * type.length == 128 &&
+          !type.floating && !type.fixed) {
+         if (util_cpu_caps.has_sse2) {
+           if(type.width == 8)
+              intrinsic = type.sign ? "llvm.x86.sse2.psubs.b" : "llvm.x86.sse2.psubus.b";
+           if(type.width == 16)
+              intrinsic = type.sign ? "llvm.x86.sse2.psubs.w" : "llvm.x86.sse2.psubus.w";
+         } else if (util_cpu_caps.has_altivec) {
+           if(type.width == 8)
+              intrinsic = type.sign ? "llvm.ppc.altivec.vsubsbs" : "llvm.ppc.altivec.vsububs";
+           if(type.width == 16)
+              intrinsic = type.sign ? "llvm.ppc.altivec.vsubsws" : "llvm.ppc.altivec.vsubuws";
+         }
       }
    
       if(intrinsic)
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_swizzle.c b/src/gallium/auxiliary/gallivm/lp_bld_swizzle.c
index 377884a..ae4033b 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_swizzle.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_swizzle.c
@@ -246,7 +246,7 @@ lp_build_swizzle_scalar_aos(struct lp_build_context *bld,
        *   YYYY YYYY .... YYYY  <= output
        */
       struct lp_type type4;
-      const char shifts[4][2] = {
+      const int shifts[4][2] = {
          { 1,  2},
          {-1,  2},
          { 1, -2},