[Mesa-dev] [PATCH] glsl: Fix type error when lowering integer divisions

Paul Berry stereotype441 at gmail.com
Fri Aug 12 10:38:35 PDT 2011

This patch fixes a bug when lowering an integer division:


to a multiplication by a reciprocal:


If x was a a plain int and y was an ivecN, the lowering pass
incorrectly assigned the type of the product to be float, when in fact
it should be vecN.  This caused mesa to abort with an IR validation

Fixes piglit tests {fs,vs}-op-div-int-ivec{2,3,4}.
 src/glsl/lower_instructions.cpp |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/src/glsl/lower_instructions.cpp b/src/glsl/lower_instructions.cpp
index 806f863..23aa19b 100644
--- a/src/glsl/lower_instructions.cpp
+++ b/src/glsl/lower_instructions.cpp
@@ -166,6 +166,10 @@ lower_instructions_visitor::div_to_mul_rcp(ir_expression *ir)
 	 op0 = new(ir) ir_expression(ir_unop_u2f, vec_type, ir->operands[0], NULL);
+      vec_type = glsl_type::get_instance(GLSL_TYPE_FLOAT,
+					 ir->type->vector_elements,
+					 ir->type->matrix_columns);
       op0 = new(ir) ir_expression(ir_binop_mul, vec_type, op0, op1);
       if (ir->operands[1]->type->base_type == GLSL_TYPE_INT) {

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